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                                                                 EXHIBIT 10.14


THIS LEASE, dated for reference purposes, the 20th day of December, 1991
between Governor Park Plaza Associates a Limited Partnership, having its
principal office at 6333 Greenwich Drive, Ste. 110, San Diego, California, and
having a Federal Tax Identification Number of #33-0142066 (hereinafter referred
to as "Landlord"), and XEROX CORPORATION, a New York corporation, having its
principal office at 800 Long Ridge Road, Stamford, Connecticut 06904
(hereinafter referred to as "Tenant").


                                  WITNESSETH:


1.       DESCRIPTION

         Landlord has constructed a development on certain land, as shown on
         Exhibit A attached hereto and made a part hereof (hereinafter referred
         to as the "Complex"), which contains parking areas, common areas and
         one or more buildings and/or future building sites, including Building
         1 containing 61,808 rentable square feet, known as Governor Park Plaza
         and located at 6333 Greenwich Drive in the City of San Diego, State of
         California, 92122 (hereinafter referred to as the "Building").


         Landlord hereby leases to Tenant and Tenant hereby leases from
         Landlord the following space in the Building, the space consisting of
         7,042 rentable square feet (6,350 usable square feet) on the first
         floor of Building 1 and known as Suite 120, as shown on Exhibit B
         attached hereto and made a part hereof (hereinafter referred to as the
         "Demised Premises"), together with the use in common with other
         tenants of the Building of the hallways, corridors, lobby, lavatories,
         elevators, stairways and other common areas and facilities of the
         Building appurtenant thereto, and together with the sidewalks,
         driveways and parking facilities provided for in Paragraph 10(h)
         hereof (all together hereinafter referred to as the "Premises").


2.       TERM

         The term of this Lease is three (3) years, to scheduled to commence on
         the first day of February, 1992 (hereinafter referred to as the
         "Commencement Date"), and to end on the thirty first day of January,
         1993 (hereinafter referred to as the "Expiration Date"), both dates
         inclusive, unless the term be extended pursuant to Paragraph 16 or
         Exhibit C hereof, or earlier terminated as provided herein.


3.       RENT

         The base monthly rental shall be fully serviced and shall be at the
         rate of:

                 $0.80 per rentable square foot for months 1 through 12,
                 $1.59 per rentable square foot for months 13 through 24,
                 $1.65 per rentable square foot for months 25 through 36,

         to be paid in advance on or before the first day of each month during
         the term hereof; provided however, that if the term of this Lease
         should commence on the date other than the first day of the month, the
         first and last month's rent shall be prorated.


4.       USE

         The Demised Premises may be used and occupied for general office
         purposes, including by way of specification (but without limiting the
         generality of the foregoing), offices, research and development,
         training, customer service demonstration areas and computer areas.
         Landlord covenants, warrants and represents that there are no zoning
         ordinances or other prohibitions restricting or limiting the use of
         the Demised Premises for the purposes herein specified.  Should any
         law, regulation or other governmental order restrict or limit Tenant's
         use of the Demised Premises, then Tenant

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         may cancel this Lease upon written notice to Landlord within ninety
         (90) days following that date upon which Tenant shall have become
         aware of such law, regulation or order and thereupon Tenant shall have
         no further obligation to Landlord either hereunder or otherwise.  In
         addition, Tenant may use all or any part of the Demised Premises for
         any lawful purpose then permitted by the zoning ordinances and the
         certificate of occupancy.

         Tenant may, if Tenant so elects, and for Tenant's sole use, install
         and operate within the Demised Premises microwave ovens and install
         and operate within the Demised Premises vending machines to dispense
         hot and cold beverages, ice cream, candy, food and cigarettes;
         such machines shall be maintained in a neat and sanitary condition and
         shall comply with all applicable laws and ordinances.


5.       PREPARATION OF PREMISES

         Landlord shall, at Landlord's sole cost and expense perform all work
         and furnish all materials necessary to complete the Demised Premises
         in accordance with Preliminary Plans and Specifications which shall be
         agreed to by Tenant and Landlord.  Such plans and specifications shall
         be deemed to be Exhibit B-1, attached hereto and made a part hereof.

         Landlord, using Landlord's Architect and Engineer, at Landlord's sole
         cost and expense, shall prepare complete final Architectural and
         Engineering drawings and Specifications (hereinafter referred to as
         "AE&S Drawings") in accordance with those Preliminary Plans and
         Specifications submitted by Tenant and approved, or deemed approved,
         by Landlord.  Landlord agrees to make revisions to the AE&S Drawings
         as required by Tenant, at no additional cost to Tenant.  The AE&S
         Drawings agreed to by Tenant and Landlord on or before DECEMBER
         26, 1991 will be the drawings provided to Landlord's General Contractor
         for the construction of the Demised Premises and such drawings shall
         be deemed to be Exhibit C, attached hereto and made a part hereof.
         Such final AE&S drawings shall be stamped, as may be necessary, by a
         licensed Engineer so that Building Permits and/or other required
         Permits may be obtained.

         Landlord shall provide in the Demised Premises, in addition to the
         Tenant Improvements herein described as Exhibit C, the following, all
         in good condition and proper working order:

         1.      Ceiling grid: material and installation.

         2.      Ceiling tile: material only.

         3.      Building standard mini blinds: material and installation, on
                 all exterior and atrium windows.

         4.      Main HVAC System to include on the floor main supply and
                 return ductwork: Branch ducts and diffusers to the space are
                 not included in the shell.

         5.      Lighting installed in accordance with the building standard
                 plan.

         6.      Dry wall, tape and bed the interior of all exterior walls,
                 cores, demising walls, and all columns.

         7.      Provide electrical service to, and a distribution panel in,
                 the Demised Premises.

         9.      Landlord shall provide an allowance towards the purchase and
                 installation of a telephone communication system to include
                 telephone sets, telecommunication wiring and labor to install
                 to be specified by Tenant as detailed in Exhibit B-1, and such
                 allowance shall not exceed $12,000.00.

         10.     Landlord shall provide an allowance towards the purchase and
                 installation of computer network cabling and such allowance
                 shall not exceed $3,000.00.

         12.     Adequate preventive measures so as to eliminate or
                 substantially reduce noise and/or vibration from external
                 sources, such as vehicular or railroad traffic.


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         13.     Complete final architectural and engineering drawings and
                 specifications, stamped as may be necessary by a licensed
                 engineer and/or architect so that building and/or other
                 required permits may be obtained.

         Landlord and Tenant acknowledge that Landlord may be performing work
         in the Building simultaneously with Tenant's work, and Landlord and
         Tenant agree to cooperate with each other in the conduct of their
         work, recognizing the amount of space each party will be working on,
         in terms of fairly allocating access to the freight elevator, truck
         loading dock and like facilities.

         If the Premises and Demised Premises are not so completed on or before
         the Scheduled Commencement Date as hereinbefore set forth, then the
         term of this Lease and the obligation of Tenant to pay rent shall not
         commence until the Premises are completed pursuant to the foregoing
         paragraph, and Landlord shall have given Tenant at least fifteen (15)
         days written notice prior to the date the Premises are so completed.
         In the event Landlord fails to so complete the Building and the
         Premises for causes beyond Landlord's control, such as strikes,
         governmental restrictions, and acts of God, then the Commencement Date
         shall be postponed for the period of such delay, provided however,
         that if the Landlord fails to so complete the Premises (for a cause
         either within or beyond Landlord's control) on or before February 1,
         1992, then Tenant, at Tenant's reasonable discretion, may cancel this
         Lease by giving written notice to Landlord and thereupon Tenant shall
         have no further obligation to Landlord either hereunder or otherwise.

         In the event the Demised Premises are not completed on or before the
         Commencement Date for the reasons set forth in the preceding paragraph
         permitting postponement of the Commencement Date, then Landlord and
         Tenant promptly shall execute a document in the form attached hereto
         as Exhibit D and made a part hereof, to establish the Commencement
         Date. In the event the delay in the Commencement Date was caused by
         Tenant, then the Expiration date shall be extended for a like period
         so as to provide for the full term as set forth in Paragraph 2 hereof,
         but in the event the delay in the Commencement Date was caused by
         force majeure or by delay by the Landlord, then Tenant shall have the
         option (a) to extend the Expiration Date by a like period so as to
         provide for the full term as set forth in Paragraph 2 hereof, or (b)
         not to extend the Expiration Date.

         Tenant hereby designates JUDY O' REILLY as its representative with
         authority to approve changes in design or construction, and to inspect
         and approve workmanship and material.  In all cases, his/her signature
         shall be final and binding upon Tenant with respect to the authority
         herein granted to him/her.  All alternates either of additions or
         deletions, agreed to between Landlord and Tenant must be in writing
         and must be agreed to by Tenant's representative to be binding.
         Tenant reserves the right to designate an alternate representative by
         notice to Landlord.

         Landlord hereby guarantees that the work shall be free from defects
         for a period of one (1) year from the completion date.  Landlord shall
         at Landlord's sole cost and expense, promptly correct any portion of
         the work found to be defective during the one (1) year period, and any
         other portion of the work damaged or destroyed in the course of such
         correction.

         Upon completion and acceptance of the Demised Premises, Landlord shall
         if requested by Tenant at no expense to Tenant furnish Tenant with a
         complete set of "As-Built" drawings setting forth all improvements to
         the Demised Premises.


6.       TELEPHONE EQUIPMENT

         Landlord shall provide suitable non-exclusive space for installation
         of Tenant's telephone relay cabinets, power panels and electric
         panels.  Such space will be in addition to the Demised Premises and
         shall be provided at no additional cost to Tenant.





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7.       MAINTENANCE AND REPAIRS

         Landlord shall, at Landlord's sole expense, maintain and repair the
         Premises and the Building in a first-class condition, with all systems
         properly functioning.  Upon notification by Tenant, Landlord shall
         promptly repair any damage to or defect in the Premises and the
         Building; provided however, that if such damage is occasioned by fault
         or neglect of the Tenant (except as provided in Paragraph 18 hereof)
         and there shall not be in effect at the time such damage occurred a
         policy or policies of insurance insuring Landlord against any loss
         resulting from such damage, then Tenant shall reimburse Landlord for
         the cost of repairs, or if the proceeds of such insurance are
         insufficient to cover the cost of such repairs, then Tenant shall
         reimburse Landlord the difference between such cost and the proceeds
         which Landlord received.


8.       ALTERATIONS

         Tenant shall have the right to make such alterations and modifications
         to the Demised Premises as Tenant may deem desirable provided such
         non-structural alterations and modifications do not exceed $5,000.00
         per occurrence.  Should Tenant desire to make any alterations or
         modifications which exceed $5,000.00 per occurrence or any structural
         alterations or modifications, then Tenant agrees to first obtain
         Landlord's consent, which consent shall not be unreasonably withheld or
         delayed.  Should Landlord fail to respond to Tenant's request within
         five (5) days, then Landlord's consent shall be deemd given.  All of
         Tenant's construction to the Demised Premises shall be performed in a
         good and workmanlike manner in accordance with applicable building
         codes, regulations and all other legal requirements.  Any damage to
         the Building resulting from such alterations or modifications shall be
         repaired at Tenant's expense.


9.       SIGNS AND BUILDING NAME

         Tenant at Landlord's expense shall have the right to be listed on the
         Building lobby directory, if any, and to have identification signs
         outside of the Demised Premises, within the Building in conformance
         with Landlord's approved signage plan for the Complex.  Tenant at
         Tenant's expense shall have the right to require to be installed
         and/or removed in conformance with Landlord's approved signage plan
         for the Complex, at Tenant's option, an illuminated or nonilluminated
         sign on an exterior wall of the Building, and/or a monument sign,
         provided such sign does not violate any governmental law, ordinance or
         regulation.


10.      SERVICES

         Landlord shall furnish the following installations and/or services to
         Tenant at Landlord's cost and expense, all of which shall be adequate
         for the intended use of the Premises and in conformity with that
         furnished in local first-class buildings of similar nature.  These
         services shall be provided between the hours of 7 a.m. to 6 p.m. on
         normal business days, and 9 a.m. to 1 p.m.. on Saturdays, except, all
         equipment necessary to operate heating, ventilating and air
         conditioning systems shall be operate sufficiently in advance and
         during these hours so as to provide such services and all cleaning
         services shall be provided before or after such hours.

         (a)     Elevator service, with a minimum of one elevator subject to
                 call at all times.

         (b)     Year round air conditioning system capable of producing and
                 maintaining the following conditions throughout the Demised
                 Premises, regardless of outside temperature.

                 (i)      Temperature and Humidity - inside temperature to be
                          maintained at:

                          Summer: 74 degrees FDB +/- 2 degrees FDB relative
                                  humidity 50% maximum.
                          Winter: 72 degrees FDB +/- 2 degrees FDB relative
                                  humidity 25% minimum.





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                 (ii)     Temperature Control - areas having excessive heat
                          gain or heat loss or are affected by solar-radiation
                          at different times of the day shall be independently
                          zoned and controlled so that the interior temperature
                          condition stipulated above can be maintained.

                 (iii)    Air Movement - in conference rooms and toilet areas,
                          a mechanical ventilation system shall be furnished to
                          provide for the exhausting of stale air and smoke as
                          well as providing a comfortable circulation of air.

                 (iv)     Drafts, Noise and Vibration - the heating, air
                          conditioning and ventilating From systems shall be
                          free from objectionable drafts, noise and vibration.

                 (v)      Filtration - all air conditioned supply air shall be
                          adequately filtered so as to maintain a clean, dust
                          free, non-toxic and odorless environment.

                 (vi)     Ventilation - the air conditioning system shall
                          supply not less than 25% of fresh air wile in
                          operation.  In toilets exhaust air quantities of at
                          least 50 cu. ft./minute for each water closet or
                          urinal or 2 cu. ft. per square foot of floor area,
                          whichever is greater, is to be provided.

                 (vii)    Service and maintain an existing stand alone air
                          conditioner in the Demised Premises commonly known as
                          a CONTEMPO unit.

         (c)     All utility services.  In addition, Landlord shall furnish, at
                 its sole cost and expense, all necessary utilities including
                 electricity, to the exterior common areas, including the
                 walkways, driveways and parking area.

         (d)     Adequate insect and vermin control.

         (e)     Adequate security services for the Premises and the Building
                 including fire and burglar alarm devices.

         (f)     Initial or first installation of lamps and/or bulbs as well as
                 future replacement, as required, of lamps and/or bulbs,
                 ballasts and starters to maintain a light level of 75 foot
                 candles at desk level.

         (g)     Landlord acknowledges that the availability of sufficient
                 parking is a material inducement to the entering into of this
                 Lease by Tenant.  Landlord represents that it has sufficient
                 parking available to provide at no cost to Tenant and for
                 Tenant's exclusive use at least 3.9 paved parking spaces for
                 every 1,000 rentable square feet in the Demised Premises of
                 which 2 spaces shall be in the open parking area and shall be
                 marked exclusive to Tenant, all of which shall be no more than
                 100 feet from any public entrance to the Building.  There
                 shall be a minimum of 350 square feet allocated for each
                 parking space including aisle and turnaround space.

         (i)     Landlord shall provide, at no expense to Tenant, cleaning
                 service, trash removal, and window washing for the Demised
                 Premises and the Premises in accordance with the Cleaning
                 Schedule marked Exhibit E and attached hereto and made a part
                 hereof.

         Tenant acknowledges that any one or more of the services provided for
         in Paragraph 10 hereof may be interrupted or suspended by reason of
         accident, repair, alterations or improvements necessary to be made,
         strikes, lockout, and except as hereinafter provided, Landlord shall
         not be liable to Tenant therefore, provided however, that (a) Landlord
         shall use its best efforts to restore such services as soon as
         reasonably possible, (b) in the event such services is not restored
         within ten (10) business days, whether or not through the fault of
         Landlord, to the extent that Tenant cannot reasonably use all or any
         part of the Premises, rent and other charges shall abate as to such
         part effective on the eleventh (11) business day and continue abated
         until such service is restored, and (c) in the event such interruption
         continues for thirty (30) calendar days, whether or not through the
         fault of Landlord, then Tenant shall have the right and option to
         cancel and terminate this Lease, on ten (10) days written notice to
         Landlord, and thereafter shall be relieved of all further liability
         under this Lease.





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11.      REDECORATING

         DELETED IN ITS ENTIRETY

12.      COMPLIANCE WITH LAW

         Landlord covenants that the Demised Premises, the Premises and the
         Building, and the fixtures and appurtenances thereto (except those
         installed by Tenant) do conform or that Landlord will promptly cause
         them to conform to every applicable requirement of law or duly
         constituted authority or the requirements of the carriers of all
         insurance on or relating to the Demised Premises, the Premises or the
         Building whether such insurance be furnished by Landlord or Tenant and
         that Landlord will, at its sole risk and expense, at all times during
         the term hereof promptly comply with all such requirements.  The
         Tenant shall comply with all applicable statutes, ordinances, rules
         and regulations of federal, state and municipal governments and all
         applicable rules and regulations of the Board of Fire Underwriters as
         such statutes, ordinances, rules and regulations pertain to Tenant's
         use of the Demised Premises.

         Landlord shall also comply with all applicable city, county, state and
         federal ordinances in effect from time to time with respect to
         facilities for the handicapped in the Demised Premises, the Premises
         and the Building.


13.      LANDLORD'S TITLE, AUTHORITY AND QUIET ENJOYMENT

         Landlord covenants and represents that it has good and marketable
         title to the Building and the Complex, free and clear of all ground
         leases, liens and mortgages or deeds of trust affecting Tenant's
         possession of the Demised Premises, Tenant's use of the Premises, or
         the rights granted to Tenant hereunder, except: a mortgage/deed of
         trust dated Nov. 2, 1987 from Landlord, as mortgagor, and NEW ENGLAND
         MUTUAL LIFE INSURANCE COMPANY, a MASSACHUSETTS CORPORATION, as
         mortgagee/beneficiary of deed of trust.

         In the event this Lease or the leasehold estate created hereunder is
         subject to the prior rights of any mortgagee/beneficiary of deed of
         trust or ground lessor, then Landlord shall secure from such
         mortgagee/beneficiary of deed of trust or ground lessor a written
         agreement in recordable form, in the form of Exhibit "F",
         Non-Disturbance and Attornment Agreement (executed and acknowledged by
         and on behalf of such mortgagee/beneficiary of deed of trust, or
         ground lessor), which provides, among other things that Tenant, so
         long as Tenant is not in default hereunder, may remain in possession
         of the Demised Premises pursuant to the terms hereof and without
         diminution of Tenant's rights should Landlord become in default with
         respect to such mortgage or ground lease or should the Premises become
         the subject of any action to foreclose any mortgage or to dispossess
         Landlord.  Such agreement shall be secured and furnished to Tenant at
         the same time this executed Lease is delivered to Tenant.

         Landlord covenants and represents that it has full and complete
         authority to enter into this Lease under all of the terms, conditions
         and provisions set forth herein, and so long as Tenant keeps and
         substantially performs each and every term, provision and condition
         herein contained on the part of Tenant to be kept and performed,
         Tenant shall peacefully and quietly enjoy the Premises without
         hindrance or molestation by Landlord or by any other person claiming
         by, through or under Landlord.


14.      SUBORDINATION

         The priority of this Lease and the leasehold estate of Tenant created
         hereunder are and shall be subject and subordinate to the lien of any
         mortgage or ground lease, whether such mortgage is placed against the
         fee or leasehold estate, which may now or hereafter affect the
         Building and to all renewals, modifications, consolidations,
         replacements and extensions thereof, and advances thereunder,
         effective upon the date the mortgagee or ground lessor, as the case
         may be, shall deliver to Tenant a written agreement in the form of
         Exhibit "F", Non-Disturbance and Attornment





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         Agreement (executed and acknowledged by and on behalf of the
         mortgagee/beneficiary of deed of trust, or ground lessor) in
         recordable form which provides, among other things that Tenant, so
         long as Tenant is not in default hereunder, may remain in possession
         of the Demised Premises pursuant to the terms hereof and without any
         diminution of the Tenant's rights should Landlord become in default
         with respect to such mortgage or ground lease or should the Premises
         become the subject of any action to foreclose any mortgage or to
         dispossess Landlord.  Any fee which Landlord's lender or ground lessor
         may charge for such agreement shall be paid by Landlord.


15.      ASSIGNMENT AND SUBLETTING

         Tenant shall have the right to assign this Lease or to sublease all or
         any portion of the Demised Premises, with Landlord's consent which
         consent shall not be unreasonably withheld or delayed.  Should
         Landlord fail to respond to Tenant's request within five (5) days
         Landlord's consent shall be deemed given.  Any such assignment or
         subletting shall not relieve Tenant of its obligations hereunder.

         In the event Tenant sells the operating unit which occupies the
         Demised Premises to another company, then anything to the contrary in
         this paragraph notwithstanding, Tenant shall have the right to assign
         this Lease to such other company, but Tenant shall not thereby be
         released of liability under this Lease.


16.      LEASE EXTENSION

         If this Lease shall not have been terminated pursuant to any
         provisions hereof and Tenant is not in default under the terms
         hereunder, then Tenant may, at Tenant's option, extend the term of
         this Lease for one (1) successive additional term of three (3) years,
         commencing on the expiration of the original term, or the immediately
         preceding additional term as the case may be, and in the event Tenant
         has elected to exercise its option to lease additional space pursuant
         to Paragraph 25 the option provided for herein shall include such
         additional space.  At least nine (9) months prior to the expiration of
         the initial term or any extended term, as the case may be, Tenant
         shall request from Landlord the fair market rental rate being charged
         in the Building, should Tenant desire to extend the term of this
         Lease.  At least eight (8) months prior to the expiration of the
         initial or any extended term Landlord shall notify Tenant, in writing,
         the applicable rental rate for the next succeeding option period.
         Tenant may exercise such option by giving Landlord written notice by a
         date which is the later to occur of (a) six (6) months prior to the
         expiration of the original term or the additional term, as the case
         may be, and (b) sixty (60) days after receipt by Tenant of Landlord's
         notice of the applicable rental rate, as hereinabove provided, and (c)
         fifteen (15) days after the fair market rental rate has been
         determined by arbitration.  Upon the giving by Tenant to Landlord of
         such written notice and the compliance by Landlord and Tenant with the
         foregoing provisions of this Paragraph 16, the term of this Lease
         shall by deemed to be automatically extended upon all the covenants,
         agreements, terms, provisions and conditions, set forth in this Lease,
         except rental which:

         (a)     During the first renewal term shall be limited to a maximum of
                 90% of the then fair market rental rate,

         (b)     Or if Tenant elects, the rental rate schedule shall be as
                 follows:
                 $1.65 per rentable square foot for months 36 through 48,
                 $1.70 per rentable square foot for months 49 through 60,
                 $1.75 per rentable square foot for months 61 through 72,

         (c)     Upon execution of this extension option, Landlord shall repaint
                 the Demised Premises with two (2) coats of prime quality paint;
                 repainting shall be performed in a workmanlike manner with a
                 minimum of interference with Tenant's normal business
                 operations and replace all carpeting, with a quality comparable
                 to the initial installation, in the Demised Premises and in any
                 adjoining lobby/reception area, and except for such terms and
                 conditions as shall be inapplicable during any additional term
                 or in connection with this Paragraph 16.





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         The term "month" as used in this paragraph shall mean (a) if the
         Expiration Date is the last day of a calendar month, a calendar month,
         or (b) if the Expiration Date is not the last day of a calendar month,
         the period between the Expiration Date and the date in the preceding
         month which is one (1) day after the date in the month of the
         Expiration Date, e.g., if the Expiration Date falls on May 19, one (1)
         "month" prior thereto would be April 20 and two (2) "months" prior
         thereto would be March 20.

         With respect to the lease extensions, the applicable "fair market
         rental rate" shall be that rate charged for space of comparable size
         and condition in comparable buildings, including the Building, located
         in the geography commonly known as the Golden Train area of the City
         of San Diego, taking into consideration the location, quality and age
         of the building, floor level, extent of leasehold improvements
         (existing or to be provided) including the amount spent by Tenant for
         leasehold improvements over building standard in the Demised Premises,
         rental abatements, lease takeover/assumptions, moving expenses and
         other concessions, term of lease, extent of services to be provided,
         distinction between "gross" and "net" lease, a base year or amount for
         escalation purposes "both operating costs and ad valorem/real estate
         taxes" and the time the particular rental rate under consideration
         becomes or is to become effective, or any other relevant term or
         condition, including any allowances for leasehold improvements, thus,
         the "fair market value" rental rate may be a rental rate with or
         without an allowance and/or with or without various other concessions
         as set forth hereinabove.

         In the event Tenant disagrees with Landlord's determination of the
         fair market rental rate, Tenant shall promptly so notify Landlord and
         Landlord and Tenant shall thereupon negotiate in good faith to attempt
         to agree upon a mutually acceptable fair market rental rate, but in
         the event agreement has not been reached within thirty (30) days after
         Tenant's receipt of Landlord's Notice, then Tenant shall have the
         option to demand arbitration as provided in Paragraph 46 hereof.

         If Tenant fails or omits to so give to Landlord the first written
         notice referred to above, it shall be deemed, without further notice
         and without further agreement between the parties hereto, that Tenant
         elected not to exercise the options granted Tenant pursuant to this
         Paragraph 16 to extend the term of this Lease for additional periods.


17.      TAXES, ETC.

         Landlord shall pay all real estate taxes, assessments, water and sewer
         rates and charges, and any other charges which may be levied, assessed
         or charged against the Building and/or the Complex.  Landlord shall
         further make all payments required to be made under the terms of any
         mortgage or deed of trust or ground lease which is now or hereafter a
         lien on the building or the Complex which is superior to this Lease
         and all payments required to be made under any ground lease.  Landlord
         shall have a reasonable time to cure a default under the terms of the
         mortgage or deed of trust, before constituting an event of default by
         Landlord as hereinafter described in Paragraph 23 of this Lease.


18.      INSURANCE AND WAIVER OF LIABILITY

         Landlord shall provide, at its expense, throughout the term of this
         Lease, comprehensive general liability insurance covering the Building
         and the Premises, except when caused by the sole negligence of Tenant
         or Tenant's failure to perform its obligations under this Lease.  The
         policy or policies evidencing such insurance shall provide that same
         may not be cancelled or amended without fifteen (15) days prior
         written notice to Tenant, and shall provide for a combined coverage of
         bodily injury and property damage in an amount not less than Five
         Million Dollars ($5,000,000).  Such policy or policies shall be issued
         by an insurance company licensed to do business in the state in which
         the Building is situate.  Upon Tenant's request, Landlord shall submit
         to Tenant suitable evidence that the foregoing policy or policies are
         in effect.

         Tenant shall provide, at its expense, throughout the term of this
         Lease, comprehensive general liability insurance covering the Building
         and the Premises when caused by the sole negligence of Tenant or
         Tenant's failure to perform its obligations under this Lease.  The
         policy or policies evidencing such insurance shall provide that same
         may not be cancelled or amended without fifteen (15) days prior
         written notice to Landlord,





                                       8
<PAGE>   9
         and shall provide for a combined coverage of bodily injury and
         property damage in an amount not less than Five Million Dollars
         ($5,000,000).  Such policy or policies shall be issued by an
         insurance company licensed to do business in the state in which the
         Building is situate.  Upon Landlord's request, Tenant shall submit to
         Landlord suitable evidence that the foregoing policy or policies are
         in effect.  Notwithstanding the foregoing, Tenant may insure the
         foregoing risks under its blanket policy, or elect to self-insure such
         risks.

         Landlord, for itself and its insurers, hereby releases Tenant with
         respect to any liability (including that deriving from the fault or
         neglect of Tenant, assignees, subtenants, its agents, employees or
         other persons under its or their direction or control) which Tenant
         might otherwise have for any damage to the Building or the Demised
         Premises by fire, other casualty or cause which Landlord could have
         covered by a standard fire insurance policy with extended coverage
         endorsement.  The term "Tenant" as used in this paragraph shall
         include any subsidiary of Tenant and any assignee or subtenant of
         Tenant.

         Landlord shall insure the Building against fire or other casualty with
         extended coverage endorsement with an insurance company selected by
         Landlord and Landlord shall cause the policy evidencing such insurance
         to include provision permitting such release of liability if such a
         provision is obtainable from such insurer at no additional expense to
         Landlord.  If such insurer will not include such a provision in such
         policy, or if the inclusion of such provision in such policy would
         involve an additional expense for Landlord, Landlord shall so notify
         Tenant within a reasonable time.  Where such a provision is obtainable
         from such insurer and Tenant notifies Landlord in writing within a
         reasonable time thereafter that Tenant desires Landlord to cause such
         a provision to be included in such policy at the expense of Tenant,
         Landlord shall cause such a provision to be included, and Tenant
         agrees to pay promptly all expenses incurred by Landlord as a result
         of such inclusion.


19.      DAMAGE

         In the event that the Building or Premises are damaged for any reason
         whatsoever and Tenant is unable, in Tenant's reasonable business
         judgement, to carry on its normal business operations for a period of
         forty five (45) days or more, Tenant's shall have the right to
         terminate this Lease by giving written notice of such termination to
         the Landlord no later than thirty (30) days after the occurrence of
         such damage.  Upon such termination, Tenant's obligations hereunder
         and each of them, including the obligation to pay rent, shall cease
         and determine as of the day the Premises were so damaged.  If in
         Tenant's reasonable business judgement, it is unable to carry on its
         normal business operations for a period of less than forty five (45)
         days because of such damage, rent shall abate (or any free rent period
         provided for in Paragraph 3 hereof shall be extended) for the period
         the Premises are untenantable.

         In the event the Premises are partially damaged by fire or other
         casualty and Tenant shall determine that it is able to carry on its
         normal business operations, Tenant shall pay rent for only such
         portion of the Premises which Tenant in its determination may
         reasonably occupy during the time required to make repairs.  All
         repairs necessary to restore the Premises to its original condition
         shall be:

         (a)     commenced within thirty (30) days after the occurrence of such
                 damage;

         (b)     performed in a diligent and workmanlike manner with material
                 of at least the same quality utilized originally in the
                 construction of the Premises;

         (c)     completed by Landlord at Landlord's sole expense with a
                 minimum of interference with Tenant's normal business
                 operations.

         If in Tenant's determination Landlord shall not have performed any of
         the above obligations in strict compliance therewith, then Tenant may,
         but shall not be required to, undertake such obligations, and all
         costs and expenses incurred by Tenant as a result thereof may be
         deducted from any rent or other payment due or to become due
         hereunder.





                                       9
<PAGE>   10
20.      CONDEMNATION

         In the event the Building or the Complex shall be condemned for public
         use or voluntarily transferred to a public or quasi-public body in
         lieu of proceeding to a judgment of condemnation, this Lease shall
         terminate and rent shall be adjusted to the date of termination.  In
         the event a portion of the Building or the Complex shall be condemned
         for public use or voluntarily transferred to a quasi-public body in
         lieu of proceeding to a judgment of condemnation and Tenant is unable,
         in Tenant's reasonable business judgement, to carry on its normal
         business operations for a period of forty five (45) day's or more,
         Tenant-shall have the right to terminate this Lease by giving written
         notice of such termination to the Landlord no later than thirty (30)
         days after the occurrence of such condemnation or transferal.  Upon
         such termination, Tenant's obligations hereunder and each of them,
         including the obligation to pay rent, shall cease and determine as of
         the date of termination.  If in Tenant's determination, it is unable
         to carry on its normal business operations for a period of less than
         forty five (45) days because of such partial condemnation, rent shall
         abate for the period the Premises are untenantable.

         In the event a portion of the Building or Complex shall be condemned
         for public use or voluntarily transferred to a public or quasi-public
         body in lieu of proceeding to a judgment of condemnation, and Tenant
         shall determine that it is able to carry on its normal business
         operations, Tenant shall pay rent for only such portion which Tenant
         in its determination may reasonably occupy after such partial
         condemnation or transfer.  All repairs necessary to restore the
         Demised Premises, Premises, Building or the Complex as nearly as
         possible to its original condition shall be:

         (a)     commenced within thirty (30) days after the taking or
                 transfer;
 
         (b)     performed in a diligent and workmanlike manner with material
                 of at least the same quality utilized originally in the
                 construction of the Building or Complex.

         (c)     completed by Landlord at Landlord's sole expense with a
                 minimum of interference with Tenant's normal business 
                 operations.

         If in Tenant's determination Landlord shall not have performed any of
         the above obligations in strict compliance therewith, then Tenant may,
         but shall not be required to, undertake such obligations, and all
         costs and expenses incurred by Tenant as a result thereof may be
         deducted from any rent or other payment due or to become due
         hereunder.  Tenant is hereby granted a lien upon any award or
         settlement resulting from the condemnation to the extent that Tenant
         has not been reimbursed for any cost or expense which Tenant may have
         incurred hereunder.

         Except as provided in the paragraph immediately preceding, Tenant
         shall not be entitled to any award or settlement resulting from the
         condemnation, provided that nothing contained herein shall be
         construed to in any way restrict or limit Tenant from asserting a
         claim for any damages resulting from the taking of any leasehold
         improvements paid for by Tenant or moving expenses incurred as a
         result of such condemnation.


21.      DEFAULT BY TENANT

         The occurrence of any one or more of the following events shall
         constitute an event of default by Tenant:

        (a)      the failure by Tenant to make any payment of rent or any
                 other payment required to be made by Tenant hereunder, as and
                 when due, where such failure shall continue for a period of ten
                 (10) days after receipt of written notice thereof by Tenant
                 from Landlord;

        (b)      the failure by Tenant to observe or perform any of the
                 covenants, conditions or provisions of this Lease where such
                 failure shall continue for a period of thirty (30) days after
                 receipt of written notice thereof by Tenant from Landlord,
                 provided, however, that if the nature of Tenant's default is
                 such that it cannot be cured solely by payment of money and
                 that more than thirty (30) days may be reasonably required for
                 such cure, then Tenant shall not be deemed to be in default if
                 Tenant shall commence such cure within such thirty (30) day
                 period and shall thereafter diligently prosecute such cure to
                 completion;





                                       10
<PAGE>   11

         (c)     (i)      the making of any general arrangement or any
                          assignment by Tenant for the benefit of creditors;

                 (ii)     the filing by or against Tenant of a petition to have
                          Tenant adjudged a bankrupt or a petition of
                          reorganization or arrangement under any law relating
                          to bankruptcy (unless, in the case of a petition
                          filed against Tenant, when such petition is dismissed
                          within ninety (90) days);

                 (iii)    the appointment of a trustee or receiver to take
                          possession of substantially all of Tenant's assets;

                 (iv)     the attachment, execution or other judicial seizure
                          of substantially all of Tenant's assets.


22.      LANDLORD'S REMEDIES

         Upon the occurrence of an event of default under this Lease by Tenant,
         then Landlord in addition to other rights or remedies it may have,
         shall have the right to terminate this Lease upon fifteen (15) days
         written notice to Tenant, and also the right, with or without
         termination of this Lease, of reentry upon and taking possession of
         the Demised Premises and Landlord may remove all persons and property
         from the Demised Premises; such property may be removed and stored in
         any other place in the Building or in any other reasonably secure
         place for the account of and at the expense and risk of Tenant.
         Tenant hereby waives all claims for damages which may be caused by the
         reentry of Landlord and taking possession of the Demised Premises or
         removing or storing the furniture and property as herein provided and
         shall save Landlord harmless from any costs or damages occasioned
         Landlord thereby, and no such reentry shall be considered or be
         construed to be a forcible entry.  Should Landlord elect to reenter,
         as herein provided, or should it take possession pursuant to legal
         proceedings or pursuant to any notice provided for by law, Landlord
         may either terminate this Lease or, Landlord may from time to time,
         without terminating this Lease, relet the Demised Premises or any part
         thereof for such term or terms and at such rental or rentals and upon
         such other terms and conditions as may be reasonable, with the right
         to make minor alterations and repairs to the Demised Premises.  Rental
         received by Landlord from such reletting shall be applied first, to
         the payment of any costs of such reletting including reasonable
         brokerage and attorney's fee; and the residue, if any, shall be held
         by Landlord and applied in payment of future rent as the same may
         become due and payable hereunder.  Should such rentals received from
         such reletting in any during month be less than one-twelfth (1/12) of
         the annual rent reserve hereunder, then Tenant shall pay such
         deficiency to Landlord.  Such deficiency shall be calculated and paid
         monthly.  No such reentry or taking possession of the Demised Premises
         by Landlord shall be construed as an election on its part to terminate
         this Lease, unless written notice of such intention be given to
         Tenant, in which event Tenant's obligations to Landlord shall
         forthwith cease, or unless the termination thereof be decreed by a
         court of competent jurisdiction.


23.      DEFAULT BY LANDLORD

         The occurrence of any one or more of the following events shall
         constitute an event of default by Landlord:

         (a)     The failure by Landlord to make any payment required to be
                 made by Landlord hereunder, as and when due, where such
                 failure shall continue for a period of ten (10) days after
                 receipt of written notice thereof from Tenant to Landlord;

         (b)     The failure by Landlord to observe or perform any of the
                 covenants, conditions or provisions of this Lease where such
                 failure shall continue for a period of thirty (30) days after
                 receipt of written notice thereof from Tenant to Landlord;
                 provided however, that if the nature of Landlord's default is
                 such that it cannot be cured solely by payment of money and
                 that more than thirty (30) days may be reasonably required for
                 such cure, then Landlord shall not be deemed to be in default
                 if Landlord shall commence such cure within such thirty (30)
                 day period and shall thereafter diligently prosecute such cure
                 to completion.





                                       11
<PAGE>   12
24.      TENANTS REMEDIES

         Upon the occurrence of an event of default under this Lease by
         Landlord, then Tenant in addition to other rights or remedies it may
         have, at Tenant's sole option, may set off any amount owed to Tenant
         by Landlord against any rent or other payment due or to become due
         hereunder or perform any obligations of Landlord (which Landlord has
         failed to perform) in which event Tenant shall have the right to set
         off any expense incurred thereby against any rent or other payment due
         or to become due hereunder.


25.      ADDITIONAL SPACE

         Landlord hereby grants to Tenant the right to lease additional space
         contiguous to the Demised Premises and any other location in Building
         1 upon the following terms and conditions:

         (a)     No later than four (4) months prior to the time additional
                 space in Building 1 by Tenant, Tenant shall notify Landlord in
                 writing that Tenant elects to exercise this right.

         (b)     Within fifteen (15) days after Landlord receives such notice,
                 Landlord shall inform Tenant in writing the exact date
                 additional space shall be available for preparation by Tenant.
                 Provided that Tenant exercises this right Between months 1 and
                 12 inclusive of this original Term Landlord agrees to
                 contribute toward the preparation of additional space the same
                 sum of dollars per rentable square foot as was required
                 buildout Tenant's original improvements multiplied by the
                 number of additional rentable square feet.  If however, Tenant
                 exercises this right between months 13 and 36 inclusive of
                 this original Term, Landlord agrees to only perform touch-up
                 painting and carpet cleaning for any additional rentable
                 square feet to be leased.  All improvements required to be
                 made hereunder shall be of the same and/or similar quality
                 required to be furnished with respect to the completion of the
                 Demised Premises.

         (c)     The rent for any additional space shall be computed at the
                 same annual rate per square foot as the rent for the space
                 described in Paragraph 1 hereof and shall commence on the date
                 the additional space has been completed in accordance with (b)
                 above as the case may be.

         (h)     The term of the Lease for such additional space shall be the
                 balance of the term of this Lease and any additional term
                 thereof.

         (i)     Landlord shall provide Tenant with additional parking spaces
                 in the event Tenant elects to lease additional space in the
                 same ratio set forth in Paragraph 10 (h).

         (j)     All of the terms and conditions of this Lease not inconsistent
                 with this Paragraph 25 shall govern the leasing of any
                 additional space.

         (k)     Any space added to the Demised Premises pursuant to this
                 Paragraph 25 shall thereafter be deemed to be a part of and
                 included in the Demised Premises.

26.      DOWNSIZE AND RETURN OF SPACE

         DELETED IN ITS ENTIRETY

27.      RIGHT OF FIRST REFUSAL TO PURCHASE

         DELETED IN ITS ENTIRETY





                                       12
<PAGE>   13
28.      FIRST RIGHT TO LEASE

         If, during the original or any additional term hereof, Landlord elects
         to lease any space in Building 2 of Governor Park Plaza, 6363
         Greenwich Drive, then Landlord shall first offer such space in writing
         to Tenant on terms and conditions no less favorable than those offered
         to third parties.  If within twelve (12) days after receipt of such
         offer, Tenant does not notify Landlord that Tenant elects to lease
         such space, then Landlord shall be relieved of any obligations to
         Tenant with regard to any such offering; provided, however, that a
         failure by Tenant to lease any specific space when so offered by
         Landlord shall not relieve Landlord of its obligation to first offer
         Tenant any other space in Building 2 if, as and when Landlord elects
         to offer such other space to third parties.


29.      RENT ABATEMENT

         Should Tenant or those holding by, through or under Tenant not occupy
         all or any portion of the Demised Premises for any period during the
         term hereof or any additional term for any reason whatsoever, then
         anything herein to the contrary notwithstanding, Landlord and Tenant
         shall mutually agree to the percentage of the monthly rent for which
         Tenant is or might be obligated to pay based on the previous 6 month
         Operating Expense history for the Complex, and which the parties agree
         constitutes the cost of providing the services set forth in Paragraph
         10 shall abate for as long as that portion of the Demised Premises are
         not so occupied.


30.      DELIVERY OF EXECUTED LEASE AND RELATED DOCUMENTS

         Within fifteen (15) days after Tenant delivers to Landlord four (4)
         duplicate originals of this Lease duly executed by Tenant, Landlord
         shall deliver to Tenant two (2) fully executed originals of this Lease
         accompanied by agreements in the Form of Exhibit "F" (Non-Disturbance
         and Attornment Agreement) duly executed and acknowledged by and on
         behalf of each mortgagee/beneficiary of deed of trust referred to in
         Paragraph 13 hereof, and if requested by Tenant, a Memorandum of Lease
         in the form of Exhibit "G" duly executed and acknowledged by and on
         behalf of Landlord (said executed Lease, Non-Disturbance Agreement(s)
         and Memorandum of Lease are together referred to herein as the Lease
         and Related Documents").  In the event Landlord shall fail to deliver
         the fully executed Lease and Related Documents as herein required,
         Tenant may, if Tenant so elects, withdraw its execution and delivery
         of this Lease by giving Landlord written notice of such withdrawal.
         Upon such withdrawal neither party shall have any rights against the
         other either hereunder or otherwise except that Landlord shall
         forthwith return to Tenant any sums which Tenant shall have paid to
         Landlord prior to such withdrawal.


31.      TERMINATION

         Landlord hereby grants to Tenant the right to terminate this Lease at
         any time during the initial term upon one hundred and eighty (180)
         days prior written notice to Landlord.  In the event Tenant elects to
         terminate the Lease as herein provided, Tenant shall pay to Landlord
         an amount equal to thirty-five percent (35%) of the annual rental set
         forth in Paragraph 3 hereof (as it may have been amended by Paragraphs
         16, 25 and 26 hereof) from the date of termination through the balance
         of the unexpired term of the Lease.  Such payment shall be made on or
         before the date such termination becomes effective.


32.      COMPETITORS OF TENANT

         DELETED IN ITS ENTIRETY





                                       13
<PAGE>   14
33.     NOTICES

        All notices shall be sent U. S. Registered Mail, Return Receipt
        Requested to the following addresses:


        TO LANDLORD:                     TO TENANT:

        Governor Park Associates         Xerox Corporation
        c/o Nexus Development Corp.      Attention: RE/GSD Lease Administration
        6333 Greenwich Dr., Ste. 110     800 Long Ridge Road    
        San Diego, CA 92122              P.O. Box 1600
                                         Stamford, Connecticut 06904

                                         WITH A COPY TO:

                                         Xerox Corporation
                                         Attention: Manager,
                                         Real Estate Operations
                                         Western United States
                                         1851 E. 1st St., Ste. 460
                                         Santa Ana, CA 92705


        Any notice shall be deemed to have been given on the date set forth on
        the Registry Receipt given to the sender at the time of mailing, except
        that for purposes of Paragraphs 21 and 23 hereof, such notice shall be
        deemed to have been received on the earlier of (a) the date set forth on
        the Return Receipt, (b) the date of delivery as shown on the Post Office
        records, or (c) the date delivery was refused as shown on the Post
        Office records.


        Except as otherwise provided in this Lease, all correspondence to Tenant
        with respect to this Lease or any of the provisions hereof shall be sent
        to the addresses of Tenant set forth above, and any and all
        correspondence sent to Tenant at the Demised Premises or any location
        other than as stated herein, and any documents signed by Tenant at the
        Demised Premises as a result thereof shall be null and void and of no
        force and effect.  Either party, by notice to the other, shall have the
        right to change the address(es) for notice(s) to be sent to such party,
        and to add or substitute entities to which a copy of any notice shall be
        sent by the other party.


34.     BROKERAGE

        Landlord and Tenant acknowledge that MR. J. WRIGHT, OF ILIFF-THORN AND
        COMPANY, is the real estate broker which brought about this lease
        transaction, and Landlord shall pay the brokerage commission to such
        broker pursuant to separate agreement.  Landlord hereby indemnities
        Tenant against the claims of any other broker arising from Landlord's
        acts, and Tenant hereby indemnifies Landlord against the claims of any
        other broker arising from Tenant's acts.


35.     ESTOPPEL CERTIFICATE

        Landlord and Tenant shall, at any time upon not less than twenty (20)
        days prior written notice, execute and deliver to a prospective new
        landlord, lender, or assignee or subtenant of Tenant, as the case may
        be, a statement in writing (i) certifying that this Lease is unmodified
        and in full force and effect (or if modified, stating the nature of such
        modification and certifying that this Lease, as so modified, is in full
        force and effect), (ii) the date to which the rent and other charges are
        paid in advance, if any, and (iii) acknowledging that there are not, to
        the party's knowledge, any uncured defaults or unfulfilled obligations
        on the part of the other party hereunder, or specifying such defaults or
        unfulfilled obligations if any are claimed.





                                       14
<PAGE>   15

36.      INDUSTRIAL DEVELOPMENT BONDS

  Landlord covenants, warrants and represents that tax exempt Industrial
  Development Bonds, sometimes referred to as Industrial Revenue Bonds
  ("I.R.B.s") were not used in financing the Complex or the Building.  If it is
  subsequently determined that tax exempt I.R.B.s were used in such financing,
  Tenant shall have the right and option to terminate this Lease and thereafter
  be relieved of all further liability hereunder.

  In the event Landlord elects to finance the Complex or Building with tax
  exempt I.R.B.s during the term (or any additional term) of this Lease and
  Tenant occupies ten percent (10%) or more of the Building or Complex, then
  Landlord shall promptly so notify Tenant and Landlord hereby indemnifies and
  holds Tenant harmless from any loss by or claim against Tenant as a result of
  such tax exempt I.R.B. financing, and Landlord hereby releases Tenant from
  any liability to Landlord as a result of such tax exempt I.R.B. financing.
  In addition, Tenant shall have the right and option to terminate this Lease,
  as hereinabove provided.


37.      ASBESTOS AND CONTAMINATION

  Landlord covenants, warrants and represents that the Premises and the
  Building are free of any friable asbestos containing materials and that any
  non-friable asbestos containing materials in the Premises or the Building are
  identified in Exhibit       attached hereto.
                        -----  
  Landlord covenants, warrants and represents that to the best of its
  knowledge, after thorough investigation, the Premises and the Building
  (including the land thereunder) do not contain any environmental contaminants
  ("toxic contamination") of any kind (including PCBs, except for PCBs that are
  totally contained within light fixtures and exterior transformers).  At any
  time during the term of this Lease, Tenant shall have the right and option,
  at Tenant's expense, to investigate the Building for the presence of asbestos
  and PCBs and to investigate the land for the presence of toxic contamination.

  Landlord agrees to indemnify and hold Tenant harmless from any claims or
  actions related to or arising out of any subsequent discovery of friable
  asbestos or toxic contamination at the Premises or the Building (including 
  the land thereunder).  In the event of such a finding, or in the event of any
  breach  of a covenant, warranty or representation by Landlord under this
  paragraph, Tenant shall have the option of terminating this Lease without
  penalty of any kind and be released from any liability under the Lease after
  the date of such termination.


38.    HOLDOVER

  If Tenant shall remain in possession of the Demised Premises after expiration
  of the original or any additional term hereof, Tenant's occupancy shall be a
  month-to-month tenancy at 1.25 times the rental rate applicable to the last
  month of the unexpired term and under all of the other terms, conditions and
  provisions hereof except those pertaining to the term of the Lease.  Landlord
  hereby grants to Tenant the right to holdover for up to three (3) months.


39.    SURRENDER

  Upon any termination or expiration of this Lease, Tenant shall surrender the
  Demised Premises in the same condition as existed at the commencement of the
  term, except for normal wear and tear and damage caused by the elements,
  casualty, or any other cause for which Tenant might not be liable, provided,
  however, that Tenant shall have the option, but not the obligation, to remove
  any or all of the improvements and alterations made to the Demised Premises by
  Tenant or at Tenant's expense.  Any damage to the Demised Premises resulting
  from the removal of such improvements or alterations shall be repaired by
  Tenant at Tenant's expense.



                                       15

<PAGE>   16
40.     ROOF-TOP ANTENNA

        DELETED IN ITS ENTIRETY

41.     MODIFICATION OF LEASE

        The terms, covenants and conditions of this Lease may not be changed
        orally but only by an instrument in writing signed by the party against
        whom enforcement of the change is sought.  The failure of either party
        hereto to insist in any one or more cases upon the strict performance of
        any term, covenant or condition of this Lease to be performed or
        observed by the other party hereto shall not constitute a waiver or
        relinquishment for the future of any such term, covenant or condition.


42.     MEMORANDUM OF LEASE

        Neither party shall record this Lease or any of the exhibits and/or
        riders attached hereto, (except that Tenant may record the executed
        Non-Disturbance and Attornment Agreement) but at the request of either
        party, Landlord and Tenant shall enter into a "short form" or Memorandum
        of Lease in recordable form, attached hereto as Exhibit "G" and made a
        part hereof, which may be recorded and which shall set forth the
        parties, the legal description of the land underlying the Building or
        Complex, a description of the Demised Premises, the Commencement Date
        and Expiration Date of the term of the Lease, and any options and/or
        restrictions in this Lease desired to be included by either party.


43.     PARAGRAPH CAPTIONS

        Paragraph captions herein are for Landlord's and Tenant's convenience
        only, and neither limit nor amplify the provisions of this Lease.


44.     ENTIRE AGREEMENT

        This Lease represents the entire agreement between Landlord and Tenant
        and supercedes all prior agreements both written and oral.  The terms,
        covenants and conditions of this Lease shall be binding upon and shall
        inure to the benefit of Landlord and Tenant and their respective
        executors, administrators, heirs, distributees, legal representatives,
        successors and assigns.  The term "Tenant" as used in this Lease shall
        include Xerox Corporation and any subsidiary (or any subsidiary of any
        subsidiary) of Xerox Corporation.


45.     CHOICE OF LAW AND INTERPRETATION

        This Lease shall be governed by the law of the State in which the
        Complex is situate.  Should any provisions of this Lease require
        judicial interpretation, it is agreed that the court interpreting or
        construing the same shall not apply a presumption that the terms of any
        such provision shall be more strictly construed against one party or the
        other by reason of the rule of construction that a document is to be
        construed most strictly against the party who itself or through its
        agent prepared the same, it being agreed that the agents of all parties
        hereto have participated in the preparation of this Lease.


46.     ARBITRATION OF DISPUTES

        All disputes between Landlord and Tenant with respect to Paragraph 16 of
        this Lease, with respect to the determination of fair market value
        rental rates, shall be decided by arbitration.  Tenant shall have the
        right, by giving written notice to Landlord, setting forth in detail the
        nature of the dispute, to request arbitration.  The dispute shall be
        submitted to arbitration as follows:

        Within fifteen (15) business days after delivery of the above notice,
        each party (Landlord and Tenant) shall appoint a person to act as an
        arbitrator in its behalf.


                                       16
<PAGE>   17
        Within five (5) business days thereafter, the two appointed arbitrators
        shall jointly appoint a third arbitrator.  The dispute shall be
        arbitrated by said three arbitrators.  A majority decision of the three
        arbitrators shall control. All of the arbitrators shall be persons
        having at least ten (10) years experience in dealing with the commercial
        leases in office buildings within the City of San Diego, State of
        California, and none shall have any interest in the Building or the
        Complex or be or have been associated or affiliated with either Landlord
        or Tenant.

        In the event Landlord and Tenant, or the two arbitrators fail or refuse
        to appoint an arbitrator within the time set forth herein, then either
        party shall have the right to petition the senior judge (in terms of
        years of service), of the United States District Court of the applicable
        Federal District in which the Building is situated to appoint such
        arbitrator and the arbitrator appointed by said judge shall serve in
        said capacity.

        NOTICE:  BY INITIALLING IN THE SPACE BELOW YOU ARE AGREEING TO HAVE ANY
        DISPUTE ARISING OUT OF THE MATTERS INCLUDED IN THE 'ARBITRATION OF
        DISPUTES' PROVISION DECIDED BY NEUTRAL ARBITRATION AS PROVIDED BY
        CALIFORNIA LAW, AND YOU ARE GIVING UP ANY RIGHTS YOU MIGHT POSSESS TO
        HAVE THE DISPUTE LITIGATED IN A COURT OR JURY TRIAL.  BY INITIALLING IN
        THE SPACE BELOW, YOU ARE GIVING UP YOUR JUDICIAL RIGHTS TO DISCOVERY AND
        APPEAL, UNLESS SUCH RIGHTS ARE SPECIFICALLY INCLUDED IN THE 'ARBITRATION
        OF DISPUTES' PROVISION.  IF YOU REFUSE TO SUBMIT TO ARBITRATION AFTER
        AGREEING TO THIS PROVISION, YOU MAY BE COMPELLED TO ARBITRATE UNDER THE
        AUTHORITY OF THE CALIFORNIA CODE OF CIVIL PROCEDURE.  YOUR AGREEMENT TO
        THIS ARBITRATION PROVISION IS VOLUNTARY.  WE HAVE READ AND UNDERSTAND
        THE FOREGOING AND AGREE TO SUBMIT DISPUTES ARISING OUT OF THE MATTERS
        INCLUDED IN THE 'ARBITRATION OF DISPUTES' PROVISION TO NEUTRAL
        ARBITRATION.


                 [SIG]                                     [SIG]                
        ----------------------                      --------------------
        INITIALLED BY LANDLORD                      INITIALLED BY TENANT



47.     EXHIBITS AND RIDERS
        Attached hereto and made a part hereof are the following:
  
        EXHIBIT A:         COMPLEX
        EXHIBIT B:         DEMISED PREMISES
        EXHIBIT B-1:       PRELIMINARY SPACE PLAN
        EXHIBIT C:         PLANS AND SPECIFICATIONS
        EXHIBIT D:         LEASE TERM AGREEMENT
        EXHIBIT E:         CLEANING SCHEDULE
        EXHIBIT F:         NON-DISTURBANCE AND ATTORNMENT AGREEMENT
        EXHIBIT G:         MEMORANDUM OF LEASE


                                       17
<PAGE>   18
IN WITNESS WHEREOF, Landlord and Tenant have duly executed this Lease as of the
day and year first above written.


<TABLE>
<S>                            <C>
WITNESS:                       GOVERNOR PARK ASSOCIATES
                               a California Limited Partnership


                                By: /s/ MICHAEL J. REIDY
-------------------------------     ---------------------------------          
                                    Michael J. Reidy
                                    Its: Managing Partner

                                                           (Landlord)


WITNESS:                       XEROX CORPORATION

         [SIG]                  By: /s/ MARK A. FLAIM
-------------------------------     --------------------------------          
                                    Mark A. Flaim
                                    Manager, Real Estate Operations
                                    Western United States

                                                           (Tenant)


</TABLE>
                                      18
<PAGE>   19
                                   EXHIBIT A

                                   "COMPLEX"







                                   [GRAPHIC]
<PAGE>   20
                                   EXHIBIT B

                               "DEMISED PREMISES"


                                   Building I
                              6333 Greenwich Drive
                              San Diego, CA 92122
                                   Suite 120
                                   1st floor








                                   [GRAPHIC]
<PAGE>   21
                                   EXHIBIT Bl

                            PRELIMINARY SPACE PLANS


                                       23

<PAGE>   22


                                   EXHIBIT D

                              LEASE TERM AGREEMENT

AGREEMENT made and entered into the _________ day of ____________________ 19__,
by and between ______________________________, a corporation/partnership,
having its principal office at
__________________________________________________ (hereinafter referred to as
"Landlord"), and XEROX CORPORATION, a New York corporation, having its principal
office at 800 Long Ridge Road, Stanford, Connecticut 06904 (hereinafter referred
to as "Tenant"),

                              W I T N E S S E T H:


WHEREAS, by Lease (hereinafter called the "Lease") made the __________ day of
____________________, 19__, Landlord demised and leased unto Tenant
certain Demised Premises in a Building known as and/or located at
________________________________________ for a term of __________ (__________)
years commencing on __________ _____, 19__, and ending on __________ _____,
19__ unless sooner terminated or extended as provided therein, and

WHEREAS, the Tenant did not enter into occupancy of the Demised Premises until
__________ _____, 19__ and

WHEREAS, pursuant to Exhibit C of the Lease, Landlord and Tenant now desire to
set forth the correct Commencement Date of the term and to adjust the
Expiration Date of the term to provide for a full term of the Lease of
____________________ (__________) years,

NOW, THEREFORE, Landlord and Tenant do hereby agree as follows:

1.       The term of the Lease commenced on ____________________, 19__
         and shall continue until ______, 19__ unless sooner terminated or
         extended as provided therein.

2.       Except as hereby amended, the Lease shall continue in full force and
         effect.

3.       This agreement shall be binding on the parties hereto, their heirs,
         executors, successors and assigns.

IN WITNESS WHEREOF, the parties hereto have caused this agreement to be duly
executed as of the day and year first above written.


Witness:

____________________                       By:____________________
                                                        (Landlord)



Witness:                                   XEROX CORPORATION



____________________                        By:____________________
                                                            (Tenant)





                                       21
<PAGE>   23
                                   EXHIBIT E
                               CLEANING SCHEDULE

NIGHTLY

(between the hours of 6:00 p.m. and 6:00 a.m., Monday through Friday, Legal
Holidays excepted).  
1.       Clean lavatories as follows:
         (a)     Sweep and wash floors, using an odorless disinfectant in wash
                 water.
         (b)     Wash and polish all mirrors, powder shelves, bright work, and
                 enamel surfaces.  
         (c)     Thoroughly scour, wash and disinfect all basins, bowls, and
                 urinals.
         (d)     Wash and disinfect all toilet seats, both sides.  
         (e)     Wash all partitions, tile walls, towel, paper, and sanitary
                 napkin dispensers, and receptacles, as required.
         (f)     Empty and clean paper towel and sanitary disposal receptacles.
         (g)     Fill toilet tissue holders, soap dispensers and towel
                 dispensers, materials to be furnished by Landlord janitorial 
                 service.
2.       Empty and clean all waste receptacles, ashtrays and sand urns.
         Utilize plastic bag liners in all waste receptacles.  
3.       Wash, clean and disinfect all water fountains and water coolers.  
4.       Hand dust all office furniture and fixtures, shelves, sills and other 
         dust collecting surfaces.  
5.       Remove all rubbish and trash from premises.  
6.       Vacuum all rugs and carpeting and remove any spots or stains.  
7.       Dust mop all uncarpeted areas, using treated mops and damp mop, as 
         necessary to remove any stains or spills.  
8.       Damp mop floors in entrance foyers, elevator lobbies, and
         public corridors, if applicable.  
9.       Wet sponge wipe table tops in employee lounge, including cleaning 
         of any spills, if applicable.  
10.      During nightly tour, close all windows and blinds, extinguish lights, 
         lock doors and report any malfunctions.  
11.      Keep locker, storage and slop sink rooms in a clean and orderly 
         manner.  
12.      Keep sidewalks and parking areas clean and rubbish free.

WEEKLY
1.       Damp mop and buff polish all uncarpeted areas.
2.       Keep lawn and landscaping properly maintained, if applicable.
3.       Wash all directory board, display, entry door, and side light glass, as
         necessary.  
4.       Remove all finger marks and smudges from doors, partitions, woodwork, 
         window ledges and window mullions.

MONTHLY
1.       All uncarpeted floor areas to be washed, waxed and machine polished.
2.       Clean air conditioning grilles and filters as required.
3.       High dusting:
         (a)     Dust in place all pictures, frames, charts, graphs and similar
                 wall hangings.  
         (b)     Dust clean all vertical surfaces, such as walls, partitions,
                 doors, books and other surfaces not reached in nightly
                 cleaning.  
         (c)     Dust clean all exposed pipes, air conditioning louvers, ducts 
                 and other areas not reached in nightly cleaning.  
         (d)     Dust clean all lighting fixtures.  
         (e)     Vacuum all mini blinds.
4.       Wash all windows inside and out as needed but in no event less than 2
         times per year.  
5.       Wash, clean, and disinfect all lavatory vinyl.

ANNUALLY
1.       Damp wipe all light fixtures, including lenses and fluorescent tubes.
2.       Shampoo all rugs and carpeting.


If the above requirements are not properly complied with and the Demised
Premises and/or the Premises are not maintained in a satisfactory manner, the
Tenant may on 21 days notice to Landlord provide its own cleaning service and
deduct the cost thereof from the rental due Landlord.





                                       22
<PAGE>   24
                                   EXHIBIT F


                                NON-DISTURBANCE
                                      AND
                              ATTORNMENT AGREEMENT


This AGREEMENT dated as of the __________ day of ____________________ 19
__________, by and between the ______________________________, having a mailing
address at ______________________________ (hereinafter referred to as
"Mortgagee") and XEROX CORPORATION, a New York Corporation, having a mailing
address at Post Office Box 1600, Stamford, Connecticut 06904 (hereinafter
referred to as "Tenant").


                              W I T N E S S E T H:

WHEREAS, Mortgagee is the holder of a first mortgage or deed of trust dated as
of the ____________________ and recorded on __________ in _______ __ County, in
an Official Record Book, __________ Page __________ on a certain building
located at ________________________________________; and

WHEREAS, Tenant entered into a Lease dated as of the __________ day of
____________________ 19 __________, with ________________________ (hereinafter
referred to as "Landlord") for ____________________ square feet in that certain
building described in the Lease (hereinafter referred to as "Building" and
Mortgagee and Tenant desire to confirm their understanding with respect to the
Lease and the rights of Tenant thereunder.


NOW THEREFORE, in consideration of One Dollar ($1.00) and other good and
valuable consideration each in hand paid to the other, the receipt and
sufficiency whereof is hereby acknowledged, Mortgagee and Tenant hereby
covenant and agree as follows:


1.     Mortgagee agrees unless Tenant shall then be in default under the Lease
       and the time to cure such default shall have expired that:


       (a) When Tenant or any person claiming through or under Tenant is deemed
           a necessary party by the court, such party may be so named or joined,
           but such naming or joinder shall not otherwise be in derogation of 
           the rights of Tenant set forth in this Agreement; and


       (b) Neither Tenant nor any person claiming through or under Tenant shall
           be evicted from the Building, nor shall the leasehold estate or
           possession of Tenant or any person claiming through or under Tenant 
           be terminated or disturbed, nor (except to the extent provided in 
           Paragraph 2 of this Agreement) shall any of the rights of Tenant 
           or any person claiming through or under Tenant, be affected in any 
           way by reason of any default or event of default under the Mortgage; 
           and in no case (except as provided in Paragraph 2 hereof) shall the 
           rights of Tenant under the Lease be diminished, reduced or adversely 
           affected in any way whatsoever by reason of any default or event of 
           default under, or foreclosure of, the Mortgage.





                                       1
<PAGE>   25
                                 EXHIBIT F

2.     If, at any time Mortgagee (or any person, or such person's successors or
       assigns, who acquired the interest of the Landlord under the Lease
       through foreclosure action of the Mortgage or otherwise) shall succeed
       to the rights of the Landlord under the Lease as a result of a default
       or event of default under the Mortgage, and if the Tenant is not then in
       default under the lease beyond the time permitted therein to cure such
       default, the (i) Lease shall not terminate, (ii) Upon receipt by Tenant
       of written notice of such succession of interest, Tenant shall attorn to
       and recognize such person so succeeding to the rights of the Landlord
       under the Lease (herein sometimes called "Successor Landlord") as
       Tenant's Landlord under the Lease, upon the then executory terms and
       conditions of the Lease and as hereinafter provided in this Paragraph 2,
       and (iii) Successor Landlord shall accept such Attornment and recognize
       Tenant as the Successor Landlord's Tenant under the Lease.  Upon such
       attornment and recognition, the Lease shall continue in full force and
       effect as, or as if it were, a direct lease between the Successor
       Landlord and Tenant upon all of the then executory terms, conditions and
       covenants(including any right under the lease on the part of Tenant to
       extend the term of the lease) as are set forth in the Lease and which
       shall be applicable after such attornment and recognition.


3.     Tenant confirms that the lien or priority of the Lease shall at all
       times continue to be subject and subordinate to (a) the lien, security
       title and security interests of the Mortgage and (b) any additional
       financing of the Building or portions thereof provided by Mortgagee and
       the liens, security titles and security interests of the documents
       evidencing and securing such additional financing, and to any increases
       therein or supplements thereto, it being understood that such
       subrogation shall not derogate any of Tenant's rights, or Landlord's
       obligations, under said Lease.


4.     Tenant certifies that there are no defaults on the part of the Landlord
       under the Lease known to Tenant, that the Lease is a complete statement
       of the agreement of the parties thereto with respect to the letting of
       the Building, that the Lease is in full force and effect and that all
       conditions to the effectiveness or continuing effectiveness thereof
       required to be satisfied at the date hereof have been satisfied.


5.     Tenant will notify Mortgagee of any default of the Landlord under the
       Lease which would entitle Tenant to cancel the Lease or abate the rent
       or additional rent payable thereunder, and agrees that notwithstanding
       any provisions of the Lease, no notice of cancellation thereof shall be
       effective unless Mortgagee has received the notice aforesaid and has
       failed within thirty (30) days of the date thereof to cure the default,
       or if the default cannot be cured within thirty (30) days, has failed to
       commence and to diligently prosecute the curing of the default which
       gave rise to such right of cancellation or abatement.  All such notices
       shall be in writing and shall be deemed to have been given when
       deposited in the United States mail, registered, postage prepaid,
       addressed as follows:


                          ______________________________
                          ______________________________
                          ______________________________
                          ______________________________


6.     The provisions of this Agreement shall be self-operative and no further
       instrument shall be necessary to effect the aforementioned attornment,
       recognition and subordination.  Nevertheless, in confirmation thereof,
       Tenant shall execute and deliver an appropriate certificate to confirm
       such attornment, recognition and subordination upon the request of
       Mortgagee or any other party to whom Tenant herein agrees to attorn.





                                       2
<PAGE>   26
                                   EXHIBIT F


7.     This Agreement shall inure to the benefit of and be binding upon the
       parties hereto and their successors and assigns.


IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the
day and year first above written.


WITNESS:



____________________                       BY:____________________
                                              (TITLE)

                                                        (MORTGAGEE)


WITNESS:                                      XEROX CORPORATION

____________________                       BY:____________________
                                              (TITLE)

                                                           (TENANT)





                                       3
<PAGE>   27

                                  EXHIBIT - G

                              MEMORANDUM OF LEASE


THIS MEMORANDUM OF LEASE dated, for reference purposes, the __________ day of
____________________, 19 __________, between _____________________ a ________
corporation/partnership, having its principal office at______________,
__________________________, __________________, hereinafter referred to as
"Landlord"), and Xerox Corporation, a New York corporation, having its principal
office at 800 Long Ridge Road, Stamford, Connecticut 06904 (hereinafter referred
to as "Tenant").


                              W I T N E S S E T H:

Landlord, in consideration of the rents, terms, agreements and conditions
contained in that certain lease between Landlord and Tenant dated the
__________ day of ____________________ 19 __________, leased to Tenant and
Tenant leased from landlord, the premises known as __________ and located in a
building (the "Building') located at  _____________,__________ as more
particularly described in Exhibit A, attached hereto and made a part hereof,
under the following terms and conditions:


1.       The term of the lease is for____________ years, commencing __________
         _____, 19 _____ and ending on __________ _____, 19_____

2.       Tenant has a right to extend the term of the lease for __________
         (_____) successive additional terms of __________ (_____) years each.

3.       Tenant has the option to expand the size of the premises leased from
         Landlord by_________________ square feet.

4.       Tenant has the option to downsize and return to Landlord,
         approximately __________ square feet of space.

5.       Tenant has the right of first refusal to purchase the building from
         Landlord.

6.       Tenant has the first right to lease additional space in the building.

7.       Tenant has the right to terminate the lease on ___________________
         (________) days prior written notice to Landlord.

8.       Tenant has the right and option to participate in the net income of
         the building in the net proceeds of refinancing, and in the net
         proceeds of sale of the building.

This Memorandum of Lease is not a complete summary of the lease.  Provisions in
this Memorandum shall not be used in interpreting the provisions of the lease.
In the event of conflict between this Memorandum and the lease, the lease shall
control.

IN WITNESS WHEREOF, Landlord and Tenant have duly executed this Memorandum of
Lease as of the day and year first above written.


                                           BY:_________________________
                                           (Title)
                                                            (Landlord)


                                           XEROX CORPORATION

                                           BY:_________________________
                                           (Title)
                                                               (Tenant)





                                       
<PAGE>   28
                                  EXHIBIT - G


STATE OF____________________

COUNTY OF___________________  SS:



On this  ___________ day of ______________, 19__, before me personally
appeared, ______________________________, to me personally known, who, being by
me duly sworn did say that he is the___________________________________
of______________________________ and that the foregoing instrument was signed
in behalf of said corporation by authority of its board of directors and said
____________________ acknowledged said instrument to be the free act and deed
of said corporation.




                                 ______________________________
                                 NOTARY PUBLIC

                                 MY COMMISSION EXPIRES:__________




STATE OF____________________
                              SS:
COUNTY OF___________________


On this___________ day of________________, 19__, before me personally
appeared,______________________________, to me personally known, who, being by
me duly sworn did say that he is the ____________________ of Xerox Corporation
and that the foregoing instrument was signed in behalf of said corporation by
authority of its board of directors and said ________________ acknowledged said
instrument to be the free act and deed of said corporation.




                                 ______________________________
                                 NOTARY PUBLIC

                                 MY COMMISSION EXPIRES:__________





                                       
<PAGE>   29


                                  EXHIBIT - G


                                   EXHIBIT A

                               LEGAL DESCRIPTION
<PAGE>   30
This Rider is made a part of Lease dated December 20, 1991 for space at 6333
Greenwich Dr., Ste. 120, San Diego, California and in the event of conflict
between this Rider and the printed portion of said Lease, this Rider shall
prevail.

OPERATING EXPENSES, REAL ESTATE TAXES AND UTILITY COSTS ESCALATION RIDER

Landlord and Tenant each acknowledge that the rent specified in Paragraph 3
does not provide for changes in Operating Expenses, Real Estate Taxes, and
Utility Costs which may hereafter pertain to the Demised Premises or the
Building.  Therefore, in addition to the rent (but not as additional rent)
Tenant shall pay Landlord its pro rata share of reasonable and customary
Operating Expenses, Real Estate Taxes and Utility Costs as hereinafter
provided:


(a)      The term "OPERATING EXPENSES" shall include the following annual
         expenses of Landlord for the operation and maintenance of the Complex
         of which the Demised Premises are a part:

         o    janitorial expenses;

         o    premiums for fire and casualty insurance required to be carried by
              Landlord pursuant to this Lease;

         o    cost of all maintenance and service agreements;

         o    cost of supplies and materials used in the operation and 
              maintenance of the Complex;

         o    employees directly and exclusively involved in the operation
              and maintenance of the Building and the Complex;

         o    all costs and expenses (other than those of a capital nature) of
              maintaining and repairing, paving and restriping, curbs,
              walkways, landscaping and the common areas of the Building,
              except in the event that during the last two (2) years of the
              term or extended term, as the case may be, Landlord elects to
              perform a single maintenance and repair project which causes
              Operating Expenses to be increased during such year by more than
              five percent (5%) over the previous years Operating Expenses,
              then in such event Tenant's obligation to reimburse Landlord for
              Operating Expenses during the year in which Landlord performed
              such single maintenance and repair project shall be limited to a
              maximum of five percent (5%) over the previous years costs for
              Operating Expenses.

         o    normal maintenance of mechanical and electrical equipment,
              including heating, ventilating, and air conditioning equipment
              but excluding capital expenditures;

         All expenses to be taken into account pursuant to this paragraph shall
         be "net" only, and for such purpose shall be deemed reduced by the
         amount of reimbursement, recoupment, payment, discount or allowance
         received or receivable by Landlord in connection with such expenses.

The term "OPERATING EXPENSES" shall exclude the following annual expenses of
Landlord:

         o    the cost of any work or service performed or rendered exclusively
              for any tenant, including Tenant, and the cost of making any
              installation or alteration to the Building and Complex which under
              generally accepted accounting principles are properly classified
              as capital expenditures;

         o    premiums for public liability insurance;

         o    brokerage commissions or other fees and other costs incurred in
              procuring tenants;

         o    management fees and administrative wages and salaries, including
              executives and officers of Landlord;

         o    depreciation, franchise or income taxes imposed on Landlord;


                                       1
<PAGE>   31
       o    advertising expenses;

       o    the cost of painting, repainting, decorating and redecorating for
            any tenant, including Tenant, of the Building and the Complex;

       o    maintenance and repair of capital items not a part of the Building;

       o    the cost of installing, operating and maintaining any specialty
            services, such as an observatory, broadcasting and/or
            telecommunication facility, data processing facility, luncheon
            club, retail store, sundries shop, newsstand, concession, athletic
            or recreational club;

       o    the cost of correcting defects in the construction of the Premises,
            Building and the Complex;

       o    the cost of any work or service performed for any tenant of the
            Building and Complex (other than Tenant) to a greater extent
            or in a materially more favorable manner than that furnished
            generally to the tenants and other occupants;

       o    the cost of any items for which Landlord is reimbursed by
            insurance, condemnation, refund, rebate or otherwise;

       o    the cost of any addition or additions to the Building or the
            Complex after the Commencement Date of this Lease;

       o    the cost of any repairs made by Landlord pursuant to the Damage or
            Condemnation paragraphs in the Lease;

       o    interest and amortization on any mortgage or deed of trust and any
            rent paid on any ground or underlying lease;

       o    any costs representing an amount paid to an entity related to
            Landlord which is in excess of the amount which would have
            been paid in the absence of such relationship;

       o    payments for rented equipment, the cost of which equipment would
            constitute a capital expenditure if the equipment were purchased;

       o    any expenses for repairs or maintenance which are covered by
            warranties, guarantees and service contracts (excluding any
            mandatory deductible);

       o    legal expenses arising out of the construction, operation, use,
            occupation or maintenance of the Building or Land or the
            enforcement of the provisions of any agreements affecting the Land
            or Building, including without limitation this Lease;

       o    increases in premiums for insurance required to be carried by
            Landlord pursuant to this Lease when such increase is
            caused by use of the Building by Landlord or any other tenant of
            Landlord which is hazardous on account of fire or otherwise, or
            premiums for any insurance carried by Landlord which is not
            required to be carried pursuant to this Lease.

       o    new items of maintenance or services for all tenants of the
            Building not included in the Operating Expense Base Year Statement,
            unless the Operating Expense Base Year Statement is revised to
            include such new items of maintenance or services.


(b)    The term "REAL ESTATE TAXES" shall mean the annual ad valorem taxes
       levied against the Building and Complex of which the Demised Premises
       are a part, by any authority having the direct power so to tax,
       including any city, county, state, or federal government, or any school,
       agricultural, transportation or environmental control agency, lighting,
       drainage or other improvement district thereof.  All expenses to be
       taken into account pursuant to this paragraph shall be "net' only, and
       for such purpose shall be deemed reduced by the amount of reimbursement,
       recoupment, payment, discount or allowance received or receivable by
       Landlord in connection with such expenses.  The term "Real Estate Taxes"
       shall not include any assessment for local improvements, license fee,
       penalty, inheritance or estate tax, any tax on Landlord's right to rent
       or other income from the Complex or on


                                       2
<PAGE>   32
       Landlord's business of leasing the Building, any penalty for delinquent
       payment of taxes, increases in taxes arising from additions or
       improvements to the Building or Complex (including leasehold improvements
       made by or for other tenants made subsequent to the Building having been
       assessed as a fully completed building), and increases in taxes due to a
       reassessment of the Building and/or Complex due to Landlord's sale
       thereof.  In the event the Building and/or land or Complex is reassessed
       (which term includes the current assessment being increased without
       reassessment) and such reassessment is greater than the prior assessment,
       then Landlord shall (a) promptly notify Tenant thereof, and (b) if in
       Tenant's reasonable determination such reassessment is excessive and
       Tenant so notifies Landlord, Landlord shall diligently protest such
       reassessment.  In the event Landlord fails so to notify Tenant, or to
       contest the reassessment (as the case may be), then Tenant's obligation
       to pay its share of Real Estate Taxes shall be computed by multiplying
       the prior assessment by the then current tax rate.


(c)    The term "UTILITY COSTS" shall include the following annual expenses of
       Landlord for the operation and maintenance of the Building and the
       Complex.  Utility charges for water, electricity, sewerage, and gas, all
       accrued and based on a calendar year operation.  All expenses to be taken
       into account pursuant to this paragraph shall be "net" only, and for such
       purpose shall be deemed reduced by the amount of reimbursement,
       recoupment, payment, discount or allowance received or receivable by
       Landlord in connection with such expenses, whether from utilities or any
       tenant in the Building.

(d)    (1)       The Base Year for Operating Expenses and Utility Costs shall
                 be the calendar year 1992.  In the event the Building was not
                 one hundred percent (100%) occupied at the commencement of the
                 Base Year, then for purposes of establishing the Base Year
                 costs, the actual Operating Expenses and Utility Costs shall
                 be adjusted upward as if the Building were one hundred percent
                 (100%) occupied.

       (2)       The Base Year for "Real Estate Taxes" shall be the later of
                 (a) the annual tax levy year next following that in which the
                 Commencement Date occurs, and (b) the annual tax levy year
                 next following the date on which the Building was fully
                 assessed as a fully completed building (including all tenant
                 leasehold improvements).

        (3)      Upon the request of either Landlord or Tenant, Landlord and
                 Tenant agree to convert the Base Year and each succeeding
                 twelve (12) month period to a calendar year basis, the
                 computation in making such a conversion to be acceptable to
                 both Landlord and Tenant.

(e)      Initially, Tenant's pro rata share shall be 6.77% calculated by
         dividing the number of rentable square feet demised to Tenant (7,042
         rentable square feet) by the number of rentable square feet in the
         Building (103,977 rentable square feet).  Tenant's pro rata share
         shall be adjusted during the term of said Lease and any renewals
         thereof by any increases or decreases in the square feet demised to
         Tenant and by any increases in the square feet in the Building.

(f)      Within ninety (90) days after the end of the Base Year and each
         anniversary thereof, the Landlord shall deliver to Tenant in Stamford,
         Connecticut (Attention: RE/GSD Lease Administration), a statement
         setting forth the amounts of Operating Expenses, Real Estate Taxes,
         and Utility Costs for the Base Year, and the amounts relative to the
         then current year, together with an invoice showing the amounts of
         increase or decrease for reimbursement.  Copies of the accounting
         statements used in the calculations and copies of receipted real
         estate tax bills, shall be furnished with the statements and invoice
         for reimbursement, and upon request by Tenant, Landlord shall submit
         additional back-up data (including copies of receipted bills) to
         permit Tenant to review such statement.  Tenant or any authorized
         agent of Tenant shall have the right, upon prior written notice, to
         audit Landlord's books at any time with respect to the Base Year or
         any subsequent year.  Upon request by Tenant, Landlord shall submit a
         statement signed by an officer (or partner, as the case may be) of
         Landlord, setting forth the percentage of occupancy of the Building at
         the Commencement of the Base Year.

(g)      In the event the Complex contains buildings in addition to the
         Building or land in excess of that required to support the Building,
         parking and common areas for the Building, and Landlord is unable to
         obtain a separate tax assessment of the Building, parking and common
         areas, the Landlord shall make a reasonable allocation for the


                                       3
<PAGE>   33
       the entire Complex.  Landlord shall also make such a reasonable
       allocation of any Operating Expenses and Utilities Costs attributable to
       the entire Complex.  In both cases, Landlord shall submit to Tenant
       sufficient back-up data as to the basis for such allocation to permit
       Tenant to determine the reasonableness of the allocation.  In the event
       that Tenant disputes the reasonableness of either such allocation,
       Landlord and Tenant agree to submit the determination of such allocation
       to arbitration in accordance with the rules of the American Arbitration
       Association.

(h)    Tenant shall pay such reimbursement due, if any, within thirty (30) days
       from receiving the remove statement, the required documentation and the
       requested documentation.  If Tenant shall dispute, in good faith, any
       reimbursement item or other sum (other than Rent) claimed by Landlord
       hereunder and Tenant shall give Landlord written notice specifying in
       reasonable detail the basis for its dispute, Tenant may withhold payment
       of the particular amount in dispute and shall not be deemed to be in
       default hereunder by reason of withholding such amount unless and until
       such dispute is determined adversely to Tenant and Tenant shall fail to
       pay the withheld amount, or the portion thereof as shall be determined to
       be payable to Landlord, within fifteen (15) days of the resolution of
       such dispute.  Tenant and Landlord shall proceed diligently to resolve
       any such dispute by agreement or arbitration in accordance with the rules
       of the American Arbitration Association.

(i)    Tenant shall have the right but not the obligation to pay any
       reimbursement due Landlord, as determined above, in twelve (12) equal
       monthly payments at the same time and in the same manner as rent.

(j)    If the first or final billing period during the term or any additional
       term of this Lease for which reimbursement may be due, shall contain less
       than twelve (12) months, the reimbursement under this Rider shall be
       prorated.

(k)    Landlord and Tenant stipulate and agree that of the rent set forth in
       Paragraph 3 hereof, $0.55 per rentable square foot per month has been
       allocated to the estimated cost of Operating Expenses, Real Estate Taxes
       and Utility Costs.  In the event the actual Operating Expenses, Real
       Estate Taxes and Utility Costs per square foot for the Building or
       Complex, as the case may be, for the Base Year or any subsequent year are
       less than $0.55 per rentable square foot per month, then the Landlord
       shall pay Tenant the difference multiplied by the number of square feet
       then leased to Tenant.  Landlord shall pay such amount to Tenant within
       thirty (30) days from sending the above statement, the required
       documentation and the requested documentation.

(1)    Tenant's obligation to reimburse Landlord for monies, under this Rider,
       shall be limited to a maximum of $0.66 per rentable square foot per month
       of space under Lease to Tenant during any one year.

(m)    Notwithstanding the foregoing provisions of this Rider, it is understood
       and agreed that in the event Landlord fails to bill Tenant for any
       amounts which may be due hereunder within four (4) months after the Base
       Year or any anniversary thereof, then Tenant shall have no liability or
       obligation to make such payment.


                                       4
<PAGE>   34
                               AMENDMENT TO LEASE


This Amendment To Lease ("Amendment") is made and entered into this first day
of June, 1994 by and among Governor Park Associates, a California limited
partnership ("Landlord"), and XEROX Corporation, New York Corporation,
("Tenant"), with regard to that certain lease dated December 20, 1991
("Lease"), and the Rider to the Lease also dated December 20, 1991 for the
premises known as suite 120 of 6333 Greenwich Drive San Diego California.


Landlord and Tenant mutually agree to amend the Lease and Rider as follows:

SECTION 1, PARAGRAPH 2 shall be amended to read:....... "consisting of 7,042
rentable square feet (6,350 usable square feet) on the first floor and 4,152
rentable square feet (3,695 usable square feet) on the-second floor of building
1 and known as suite 120 and suite 250 respectively.

SECTION 2 shall be amended to read: .... ("Commencement Date"), and to end on
the 31st day of January, 2000.

SECTION 3 shall be amended to read: The initial monthly base rent for the
extended term shall be fully serviced and shall be in the amount of $13,096.68
during the first year of the extended lease term.  The rent shall be paid in
advance on or before the first day of each month during the term hereof;
provided however, that if the term of this lease should commence on the date
other than the first day of the month, the first and last month's rent shall be
prorated.  Beginning February 1, 1997 and annually thereafter, the rent shall
be increased by 4%, effective the first day of February.

SECTION 5 shall be amended to read: Landlord's Contractor shall construct
Tenant's interior improvements in accordance with plans and specifications
approved by the Tenant.

SECTION 10 (c) "SERVICES" shall be amended to read "All utility services.  In
addition, Landlord shall furnish, at its sole cost and expense, all necessary
utilities including electricity to the common areas of the premises, including
the walkways, driveways and parking areas.  Tenant shall pay costs of
separately metered electricity consumed within its suite.

SECTION 16 "LEASE EXTENSION" shall be deleted and amended to read:

LEASE EXTENSION

If this Lease shall not have been terminated pursuant to any provisions hereof,
then Tenant may, at Tenant's option, extend the term of this Lease for one (1)
successive additional term of
<PAGE>   35
XEROX
Amendment to Lease
June 1, 1994
page two


three (3) years, commencing on the expiration of the original term, or the
immediately preceding additional term as the case may be.  Tenant may exercise
such option by giving Landlord written notice at least six (6) months prior to
the expiration of the original term, as the case may be and in the event Tenant
has elected to exercise its option to lease additional space pursuant to
Paragraph 25, the option provided for herein shall include such additional
space.  Upon the giving by Tenant to Landlord of such written notice the
compliance by Tenant with the foregoing provisions of this Paragraph 16, this
Lease shall be deemed to be automatically extended upon all the covenants,
agreements, terms provisions and conditions, set forth in this Lease, except
rental which:

(a)      During the extension option shall be limited to the base rent then in
effect in the last year of the initial extended Lease term, and

(b)      Upon execution of this extension option, Landlord shall repaint the
Demised premises with two (2) coats of prime quality paint; repainting shall be
performed in a workmanlike manner with a minimum of interference with Tenant's
normal business operations and replace all carpeting, with quality comparable
to the initial installation, in the Demised premises and in any adjoining
lobby/reception area, and

except for such terms and conditions as shall be applicable during any
additional term in connection with this Paragraph 16.  If Tenant fails or omits
to so give to Landlord the first written notice referred to above, it shall be
deemed, without further notice and without further agreement between the
parties hereto, that Tenant elected not to exercise the options granted Tenant
pursuant to this Paragraph 16, to extend the term of this lease for additional
periods.

The term "month" as used in this paragraph shall mean (a) if the Expiration
Date is the last day of a calendar month, a calendar month, or (b) if the
Expiration Date is not the last day of a calendar month, the period between the
Expiration Date and the date in the preceding month which is one (1) day after
the date in the month of the Expiration Date, e.g., if the Expiration Date
falls on May 19, one (1) "month" prior thereto would be April 20 and two (2)
"months" prior thereto would be March 20.
<PAGE>   36
XEROX
Amendment to Lease
June 1, 1994
page three


In the event this Lease is extended pursuant to the terms of this Paragraph 16,
then the BASE YEAR OR EXPENSE STOP that shall be used during any such extended
term shall be the amount of Operating Expenses, Real Estate Taxes and Utility
Costs required to be paid by Tenant pursuant to the terms of the Rider for the
twelve (12) month period immediately preceding the beginning of such extended
term (or the immediately preceding calendar year of the operating expense
payment period has been converted to a calendar year).


SECTION 31 "TERMINATION" shall be amended to read "Landlord hereby grants to
Tenant the right to terminate this lease at any time after January 31, 1998
upon one hundred and eighty (180) days prior written notice to Landlord.  In
the event Tenant elects to terminate the lease as herein provided, Tenant 
shall pay to Landlord an amount equal to thirty-five percent (35%) of the 
annual rental set forth in paragraph 3 hereof (as it may have been amended by 
Paragraphs 16, 25 and 26 hereof) from the date of termination through the 
balance of the unexpired term of the lease.  Such payment shall be made on or 
before the date such termination becomes effective.

SECTION 34 is amended to read "Landlord and Tenant acknowledge that Terrence
McGrath of COMCORE-Colliers International represents the Tenant in this lease
transaction and Landlord shall pay the brokerage commission pursuant to a
separate agreement.  Landlord hereby indemnifies Tenant against claims of any
Broker arising from this lease transaction.


THE RIDER TO THE LEASE DATED DECEMBER 20, 1991 AND MADE A PART THEREOF SHALL
HEREBY BE AMENDED AS FOLLOWS:

The term "Utility Costs" as utilized throughout this Rider is mutually
understood to mean common area utility costs as distinguished from separately
metered utilities within the Tenant's suite.

SECTION (d) (1) OF THE RIDER shall be amended to read "The Base Year for
Operating Expenses and Utility Costs shall be the Calendar year 1994." ......
<PAGE>   37
XEROX
Amendment to Lease
June 1, 1994
page four


SECTION (e) OF THE RIDER shall be amended to read "Initially, Tenant's pro rata
share shall be 10.72% calculated by dividing the number of rentable square feet
demised to Tenant (11,194 rentable square feet) by the number of rentable
square feet in the complex (103,977 rentable square feet)" ....

SECTION (k) OF THE RIDER SHALL BE DELETED AND AMENDED TO READ, "Landlord and
Tenant stipulate and agree that of the rent set forth in Paragraph 3 hereof,
$0.325 per rentable square foot per month has been allocated to the estimated
cost of Operating Expenses, Real Estate Taxes and Common Area Utility Costs.
In the event the actual Operating Expenses, Real Estate Taxes, and Common Area
Utility Costs per Square foot for the Building or Complex, as the case may be,
for the Base Year or any subsequent year are less than $0.325 per rentable
square foot per month, then the Landlord shall pay Tenant the difference
multiplied by the number of square feet then leased to Tenant.  Landlord shall
pay such amount to Tenant within thirty (30) days from sending the above
statement, the required documentation and the requested documentation.

SECTION (1) OF THE RIDER SHALL BE DELETED AND AMENDED TO READ, "Tenant's
obligation to reimburse Landlord for monies, under this Rider, shall be limited
to a maximum of $0.50 per rentable square foot per month of space under Lease
to Tenant during any one year.

ALL OTHER TERMS AND CONDITIONS OF THE LEASE SHALL REMAIN IN FULL FORCE AND
EFFECT.


WITNESS WHEREOF, Landlord and Tenant have duly executed this Amendment To Lease
as of the day and year first above written.


GOVERNOR PARK ASSOCIATES            XEROX CORPORATION

/s/ MICHAEL J. REIDY                /s/ MARK A. FLAIM
------------------------            ----------------------
BY: MICHAEL J. REIDY                BY: MARK A. FLAIM
ITS: MANAGING PARTNER               MANAGER, REAL ESTATE
(LANDLORD)                          OPERATIONS WESTERN
                                    UNITED STATES (TENANT)
<PAGE>   38
                   SECOND AMENDMENT TO OFFICE BUILDING LEASE

         This Second Amendment dated January 31, 1995 will modify the office
building lease between Governor Park Plaza Associates, a California limited
partnership, as Landlord, and XEROX Corporation, a New York Corporation, as
Tenant, dated December 20, 1991, and amended June 1, 1994.  In the event of
conflict between the terms and conditions of the Lease Agreement and this
Second Amendment, the terms and conditions of this Second Amendment shall
control.

SECTION 1, PARAGRAPH 2 shall be amended to read:..... "consisting of 14,727
rentable square feet (13,106 usable square feet) on the first floor of building
1 and known as suite 100 and 120."

SECTION 3 shall be amended to read: "The initial monthly base rent for the
extended term shall be fully serviced (except as provided in the Amendment to
Lease, Section 10) and shall be in the amount of $17,230.59 during the first
year of the extended lease term.  The rent shall be paid in advance on or
before the first day of each month during the term hereof; provided however,
that if the term of this lease should commence on the date other than the first
day of the month, the first and last month's rent shall be prorated.  Beginning
February 1, 1997 and annually thereafter, the rent shall be increased by 4%,
effective the first day of February."

The terms of this Second Amendment will become effective on March 1, 1995,
which is Tenant's estimated occupancy date of suite 100. On that same date, per
the terms of this Second Amendment as stated in Section 1 above, Tenant's lease
of the 4,152 square feet known as suite 240 will become void.

Landlord agrees to build-out suite 100 to mutually agreeable specifications.
Tenant agrees to pay for $3,169.50 of the costs to reconfigure suite 100.

ALL OTHER TERMS AND CONDITIONS OF THE LEASE SHALL REMAIN IN FULL FORCE AND
EFFECT.

WITNESS WHEREOF, Landlord and Tenant have duly executed this Second Amendment
to Lease as of the day and year first above written.


                                        DOCUMENT SCIENCES CORPORATION,
GOVERNOR PARK ASSOCIATES                A XEROX COMPANY

/s/  MICHAEL J. REIDY                   /s/  TONY N. DOMIT
--------------------------              ------------------------------
BY:  MICHAEL J. REIDY                   BY:  TONY N. DOMIT
ITS: MANAGING PARTNER                   ITS: CEO AND PRESIDENT
(LANDLORD)
<PAGE>   39
                    FOURTH AMENDMENT TO OFFICE BUILDING LEASE




Fourth Amendment Dated January 30, 1997 to Office Building Lease Dated December
20, 1991 Between Governor Park Associates, a California Limited Partnership, as
Landlord and Document Sciences Corporation, Identified in the Original Lease
Document as Xerox Corporation, a New York Corporation, as Tenant and Further
Amended June 1, 1994 (First Amendment), January 3, 1995 (Second Amendment)and
July 1, 1996 (Third Amendment) for That Certain Property Commonly Known as 6333
Greenwich Drive, Suite 120, in the City of San Diego, County of San Diego, State
of California.


In the event of conflict between the terms and conditions of the Lease
Agreement, the First, Second and Third Amendments and this Fourth Amendment, the
terms and conditions of this Fourth Amendment shall control.


SECTION #1, PARAGRAPH #2, DESCRIPTION:

Section # 1, Paragraph #2 shall be amended to read in full: "The Leased Premises
for Tenant shall consist of Suite 100 consisting of approximately 14,727
rentable square feet in addition to Suite 200 also located in the 6333 Greenwich
Drive office building consisting of approximately 15,526 rentable square feet.
Additionally, this Lease shall include the Premises known as Suite 270 in the
6363 Greenwich Drive office building consisting of approximately 2,849 rentable
square feet. In total, the Leased Premises consists of approximately 33,102
rentable square feet."


SECTION #2, TERM:

The term shall be amended to read in full: "The Lease for the Premises as
outlined in Section # 1, Paragraph #2, Description, shall be modified to five
(5) years scheduled to commence on March 1, 1997 (hereinafter referred to as the
"Commencement Date") and to end on February 28, 2002 (hereinafter referred to as
the "Expiration Date"). Both dates inclusive, unless the term is extended
pursuant to Paragraph # 16 as outlined in this Fourth Amendment."


SECTION #3, RENT:

Section #3 shall be amended to read in full: "The initial monthly base rent for
the extended term shall be fully serviced (except as provided in the Amendment
to Lease, Section #10) and shall increase according to the following schedule:


         Months 1-12       $1.069 per rentable square foot per month
         Months 13-24      $1.112 per rentable square foot per month
         Months 25-36      $1.156 per rentable square foot per month
         Months 37-48      $1.202 per rentable square foot per month
         Months 49-60      $1.251 per rentable square foot per month

"The aforementioned rental schedule includes the Tenant contracting directly
with the local gas and electric and/or utility company for their separately
metered utilities."


SECTION #5, PREPARATION OF PREMISES:

Section #5 shall be amended to read in full: "Tenant shall, at Tenant's sole
cost and expense, perform all work and furnish all materials necessary to
complete any construction related to improving the subject Premises in
accordance with preliminary plans and specifications which shall be agreed to by
Landlord and Tenant. Such plans and specifications shall be deemed to be Exhibit
"B-1 " (Preliminary Space Plan) attached hereto and made a part hereof."


"Tenant, using Tenant's architect and engineer at Tenant's sole cost and
expense, shall prepare complete and final architectural and engineering drawings
and specifications 
<PAGE>   40
(hereinafter referred to as "AE&S Drawings") in accordance with those
preliminary plans and specifications submitted by Tenant and approved or deemed
approved by Landlord. The AE&S Drawings agreed to by Landlord and Tenant will be
the drawings provided to the general contractor for the construction of the
demised Premises. Such final AE&S Drawings shall be stamped as may be necessary
by a licensed engineer so that building permits and/or other required permits
may be obtained."


"Landlord and Tenant mutually agree that Tenant will contribute One Hundred
Sixty Thousand and No/100ths ($160,000.00) Dollars or Four and 83/100ths ($4.83)
Dollars per rentable square foot towards the construction of tenant improvements
within the subject Premises. In the event any portion of this One Hundred Sixty
Thousand and No/l00ths ($160,000.00) Dollars is not spent on the construction of
tenant improvements within the subject Premises, Landlord and Tenant further
agree that the rental schedule outlined in Section #3 above shall adjust. To the
extent that Tenant spends less than the full One Hundred Sixty Thousand and
No/l00ths ($160,000.00)Dollars, the rent shall be adjusted upwards. The monthly
upward adjustment will be calculated by adjusting the rent upwards by 2 for
every One and No/l00ths ($1.00) Dollar per square foot not spent. In other
words, if Tenant were to spend Three and 83/100ths


Fourth Amendment Dated January 30, 1997 to Office Building Lease Dated December
20, 1991 Between Governor Park Associates, a California Limited Partnership, as
Landlord and Document Sciences Corporation, Identified in the Original Lease
Document as Xerox Corporation, a New York Corporation, as Tenant and Further
Amended June 1, 1994 (First Amendment), January 3, 1995 (Second Amendment) and
July 1, 1996 (Third Amendment) for That Certain Property Commonly Known as 6333
Greenwich Drive, Suite 120, in the City of San Diego, County of San Diego, State
of California.

($3.83) Dollars per rentable square foot (One Hundred Twenty-Six Thousand Seven
Hundred Eighty and 66/100ths [$126,780.66] Dollars) instead of the full Four and
83/100ths ($4.83) Dollars per rentable square foot (One Hundred Sixty Thousand
and No/100ths [$160,000.00] Dollars) of additional tenant improvements, then the
One and No/100ths ($ 1.00) Dollar per rentable square foot of unspent monies
would equate to 2 cents per square foot per month that would be added to the
base monthly rent which then equals a base rent of $1.0869 per rentable square
foot per month plus utilities or Thirty-Five Thousand Nine Hundred Seventy-Eight
and 56/100ths ($35,978.56) Dollars per month."


SECTION #14, SUBORDINATION:

The attached Nondisturbance, Subordination & Attornment Agreement (Exhibit "F")
shall overrule Paragraph #14 of the original Lease.

SECTION #16, LEASE EXTENSION:

This Section shall be amended to read in full: "Provided Tenant is not in
default under the terms hereunder regarding the Premises outlined herein, then
Tenant may, at Tenant's option, extend the Lease for one (1) successive
additional term of five (5) years commencing on the expiration on the Extension
Term. Tenant shall be required to provide at least one hundred twenty (120) days
written notice prior to the expiration of the lease term. Tenant shall then
request from Landlord the "fair market rental rate" being charged in the
Building should the Tenant desire to extend the term of the Lease. In the event
Tenant rejects Landlord's definition of "Fair Market Rental Rate" and cannot
reach an acceptable agreement per the foregoing paragraphs in this Section,
then said option shall lapse. Tenant shall not be required to exercise said
option."

"The term "month" as used in this Paragraph shall mean (a) if the expiration
date is the last day of a calendar month, a calendar month, or (b) if the
expiration date is not the last day of a calendar month, the period between the
expiration date and the date in the preceding month which is one (1) day after
the date in the month of the expiration date, e.g., if the expiration date falls
on May 19, one (1) "month" prior thereto would be April 20 and two (2) "months"
prior thereto would be March 20."

"With respect to the lease extensions, the applicable "fair market rental rate"
shall be that rate charged for space of comparable size and condition in
comparable buildings, including the Building, located in the geography commonly
known as the Golden Triangle area of the City of San Diego, taking into
consideration the location, quality and age of 
<PAGE>   41
the building, floor level, extent of leasehold improvements (existing or to be
provided) including the amount spent by Tenant for leasehold improvements over
building standard in the Demised Premises, rental abatements, lease
takeover/assumptions, moving expenses and other concessions, term of lease,
extent of services to be provided, distinction between "gross" and "net" lease,
a base year or amount for escalation purposes "both operating costs and ad
valorem/real estate taxes" and the time the particular rental rate under
consideration becomes or is to become effective, or any other relevant term or
condition, including any allowances for leasehold improvements, thus, the "fair
market value" rental rate may be a rental rate with or without an allowance
and/or with or without various other concessions as set forth hereinabove."

"In the event Tenant disagrees with Landlord's determination of the fair market
rental rate, Tenant shall promptly so notify Landlord and Landlord and Tenant
shall thereupon negotiate in good faith to attempt to agree upon a mutually
acceptable fair market rental rate, but in the event agreement has not been
reached within thirty (30) days after Tenant's receipt of Landlord's Notice,
then Tenant shall have the option to demand arbitration as provided in Paragraph
46 of the Lease."

"If Tenant fails or omits to so give to Landlord the first written notice
referred to above, it shall be deemed, without further notice and without
further agreement between the parties hereto, that Tenant elected not to
exercise the options granted Tenant pursuant to this Paragraph 16 to extend the
term of this Lease for additional periods."

"Any additional improvements required at the time of renewal shall be negotiated
between Landlord and Tenant."

Fourth Amendment Dated January 30, 1997 to Office Building Lease Dated December
20, 1991 Between Governor Park Associates, a California Limited Partnership, as
Landlord and Document Sciences Corporation, Identified in the Original Lease
Document as Xerox Corporation, a New York Corporation, as Tenant and Further
Amended June 1, 1994 (First Amendment), January 3, 1995 (Second Amendment) and
July 1, 1996 (Third Amendment) for That Certain Property Commonly Known as 6333
Greenwich Drive, Suite 120, in the City of San Diego, County of San Diego, State
of California.


SECTION #34, BROKERAGE:

This Section shall be amended to read in full: "Landlord and Tenant acknowledge
that Grubb & Ellis represents Document Sciences Corporation (previously the
XEROX Corporation) and Landlord is represented by CB Commercial Real Estate
Group, Inc. in this lease transaction. Landlord and Tenant agree that all
commissions are to be paid by Tenant in lieu of rent in accordance with the
attached "Assignment of Rents". Landlord hereby indemnifies Tenant against the
claims of any other broker arising from Landlord's acts and Tenant hereby
indemnifies Landlord against the claims of any other broker arising from
Tenant's acts."

SECTION #47, EXHIBITS & RIDERS:

The following Exhibits shall be amended as follows:

1.       The original Exhibits "B" and "B-1 " shall be replaced by the attached
         Exhibit "B-1" " Tenant's preliminary Space Plan.

2.       Exhibit "C" shall be deleted.

3.       Exhibit "D" shall be deleted.

4.       The original Exhibit "F" shall be replaced by the attached Exhibit "F"
         Subordination, Attornment & Nondisturbance Agreement.

5.       Exhibit "H" shall be known as the Master Lease.

6.       Exhibit "I" shall be known as the Assignment of Rents Between Landlord,
         Tenant and Grubb & Ellis.

7.       Exhibit "J" shall be known as the Assignments of Rents Between
         Landlord, Tenant and CB Commercial Real Estate Group, Inc.
<PAGE>   42
SECTION (e) OF LEASE RIDER:

Section (e) of the Rider shall be amended to read in full: "Tenant's pro rata
share shall be 31.83%, calculated by dividing the number of rentable square feet
demised to Tenant (33,102 rentable square feet) by the number of rentable square
feet in the complex (103,977 rentable square feet)..."

ADDENDUM #1:

The attached Assignment of Rents marked Exhibit "I" and "J", respectively, are
attached hereto and made a part hereof Landlord and Tenant agree to abide by the
terms and conditions of said Assignment of Rent.

All other terms and conditions of the Lease shall remain in full force and
effect.

WITNESS WHEREOF, Landlord and Tenant have duly executed this Fourth Amendment to
Lease as of the day and year first above written.

LANDLORD                                    TENANT
GOVERNOR PARK ASSOCIATES,                   DOCUMENT SCIENCES CORPORATION,
a California Limited Partnership            IDENTIFIED IN THE ORIGINAL LEASE
                                            DOCUMENT AS XEROX CORPORATION,
                                            a New York Corporation



By: /s/ Michael J. Reidy                    By: /s/ Tony N. Domit
   --------------------------                   --------------------------
        Michael J. Reidy                            Tony N. Domit

Title: Manager                              Title: CEO and President

Date: 2-25-97                               Date: 2/20/97


EXHIBIT "B-1"

IMAGE NOT SHOWN
<PAGE>   43




EXHIBIT "B-1"

IMAGE NOT SHOWN
<PAGE>   44
EXHIBIT B-1

IMAGE NOT SHOWN




<PAGE>   45
EXHIBIT B-1

IMAGE NOT SHOWN
<PAGE>   46
                                  EXHIBIT "B-2"

                              TENANT SPECIFICATIONS
                               GOVERNOR PARK PLAZA


DEMISING PARTITION (ONE HOUR SEPARATION)

8.       2 1/2", 25 gauge metal studs-24" on center.
9.       5/8" drywall one (1) layer each side of studs.
10.      Height required from floor slab to underside of structure.
11.      Partition taped smooth to receive two (2) coast of flat latex paint or
         wall covering.
12.      2 1/2" batt insulation between studs for sound attenuation.

INTERIOR PARTITION (NON-RATED PARTITION):

1.       2 1/2", 25 gauge metal studs-24" on center.
2.       5/8" drywall one (1) layer each side of studs.
3.       Height required from floor slab to ceiling grid -- 9'.
4.       Partition taped smooth to receive two (2) coast of flat latex paint or
         wall covering.

CORRIDOR DOOR ASSEMBLY COMMON AREAS ONLY 20 MIN. RATED ASSEMBLIES:

1.       3'0" X 8'10" X 1 3/4" solid core red oak rift cut veneer, 20 min.
         labeled.
2.       One (1) lockset-Falcon, lever type, mortise lock set with Finish: #26D.
3.       One (1) door closer, handicap approved.
4.       One (1) door stop floor mounted with Finish: #26D.
5.       Frame to be one (1) hour rated with paint grade finish, Timely frame or
         approved equal.

INTERIOR DOOR ASSEMBLY:

1.       3'0" X 8'10" X 1 3/4" solid core red oak rift cut veneer, 20 min.
         labeled.
2.       Timely frames factory hard bronze duranodic finish.
3.       Two (2) pars 4" X 4" butts
4.       One (1) latch set-Schlage 03, lever type, mortise latch set, Finish:
         #626.
5.       One (1) door stop wall mounted, Finish: #26D.

ELECTRICAL SERVICE:

1.       One (1) sub-panel in each space, including a sub-feed to meter room.
2.       One (1) HVAC disconnect/units.

2' X 4' FLUORESCENT LIGHT FIXTURES:

1.       2'X 4' with energy saving ballast and lamps, acrylic prismatic lens,
         with hinged door, Lithonia or equal, 4 tube fixture.
2.       Lamps to be included.
3.       Conduit and hook-ups to existing J-box.

LIGHT SWITCH ASSEMBLY:

1.       20 amp specification grade, quiet type switches rated 110 and 208 volts
         AC.
2.       Furnish switches with ivory handles.
3.       Where required, furnish two (2) pole, three (3) way and four (4) way
         switches.
4.       Plates shall be ivory, smooth plastic, specification grade, equal to
         Sierra P-line.

ELECTRICAL WALL OUTLET:

1.       15 amp, two (2) pole, three (3) wire grounding type, specification
         grade, rated 125 volts.
2.       Conductors terminated in side screws.
3.       Duplex.
4.       Mounted vertically.
5.       Ivory, smooth plastic, specification grade equal to Sierra P-line.
6.       Outlet height at 15" AFF to bottom of rough-in box.
<PAGE>   47
TELEPHONE WALL OUTLET:

1.       Use 4" minimum square box with single plaster ring and pull string.
2.       3/4" metal conduit from outlet box to terminate above ceiling.
3.       Cover plate with 3/8" bush hold, ivory, smooth plastic, specification
         grade equal to Sierra P-line.
4.       Outlet height at 15" AFF to bottom of rough-in box.

ACOUSTICAL CEILING:

1.       2' x 2' x 5/8" revealed edge, Armstrong Cortega.
2.       Chicago; white exposed ceiling grid, 800 series or equal.
3.       Ceiling height to be 9'0" above concrete slab.

HEATING & AIR CONDITIONING DISTRIBUTION:

1.       Furnish and install low pressure distribution duct work.
2.       Furnish and install supply air registers.
3.       Furnish and install return air grilles and return ducts.
4.       Install thermostats on the walls.
5.       Balance system in accordance with engineering plans and submit written
         balance report.
6.       Building "pre-zoned" in base building.
7.       Allow for engineering and drawing plans.

FLOOR COVERING:

1.       Carpet; Design Weaver, New Tempest or Atlas Mayfair, color to be
         selected by Tenant.
2.       Glue direct.
3.       VCT: Armstrong Excelon

CARPET BASE:

1.       2 1/2" Burke or Ropper Rubber carpet base.

PAINTING:

1.       All paint to be Frazee (colors to follow).
2.       Minimum two (2) coast flat vinyl wall paint.

WINDOW TREATMENTS:

1.       Vertical blinds, 3 1/2" PVC grey vanes.
<PAGE>   48
                                    EXHIBIT H


THIS LEASE, dated for reference purposes, the 20th day of December, 1991 between
Governor Park Plaza Associates a Limited Partnership, having its principal
office at 6333 Greenwich Drive, Ste. 110, San Diego, California, and having a
Federal Tax Identification Number of #33-0142066 (hereinafter referred to as
"Landlord"), and XEROX CORPORATION, a New York corporation, having its principal
office at 800 Long Ridge Road, Stamford, Connecticut 06904 (hereinafter referred
to as 'Tenant').


                                   WITNESSETH:


1.       DESCRIPTION

         Landlord has constructed a development on certain land, as shown on
         Exhibit A attached hereto and made a part hereof (hereinafter referred
         to as the "Complex"), which contains parking areas, common areas and
         one or more buildings and/or future building sites, including Building
         1 containing 61,808 rentable square feet, known as Governor Park Plaza
         and located at 6333 Greenwich Drive in the City of San Diego, State of
         California, 92122(herein after referred to as the "Building").

         Landlord hereby leases to Tenant and Tenant hereby leases from Landlord
         the following space in the Building, the space consisting of 7,042
         rentable square feet (6,350 usable square feet) on the first floor of
         Building 1 and known as Suite 120, as shown on Exhibit B attached
         hereto and made a part hereof (hereinafter referred to as the "Demised
         Premises'), together with the use in common with other tenants of the
         Building of the hallways, corridors, lobby, lavatories, elevators,
         stairways and other common areas and facilities of the Building
         appurtenant thereto, and together with the sidewalks, driveways and
         parking facilities provided for in Paragraph 10 (h) hereof (all
         together hereinafter referred to as the "Premises").

[INITIAL STAMP OMITTED]


2.       TERM

         The term of this Lease is three (3) years, to scheduled to commence on
         the first day of February, 1992 (hereinafter referred to as the
         "Commencement Date"), and to end on the thirty first day of January,
         1995 (hereinafter referred to as the "Expiration Date"), both dates
         inclusive, unless the term be extended pursuant to Paragraph 16 or
         Exhibit C hereof, or earlier terminated as provided herein.

3.       RENT

         The base monthly rental shall be fully serviced and shall be at the
         rate of:

                  S0.80 per rentable square foot for months 1 through 12
                  S1.59 per rentable square foot for months 13 through 24,
                  S1.65 per rentable square foot for months 25 through 36,

         to be paid in advance on or before the first day of each month during
         the term hereof; provided however, that if the term of this Lease
         should commence on the date other than the first day of the month, the
         first and last month's rent shall be prorated.

4.       USE

         The Demised Premises may be used and occupied for general office
         purposes, including by way of specification (but without limiting the
         generality of the foregoing), offices, research and development,
         training, customer service demonstration areas and computer areas.
         Landlord covenants, warrants and represents that there are no 
<PAGE>   49
         zoning ordinances or other prohibitions restricting or limiting the use
         of the Demised Premises for the purposes herein specified. Should any
         law, regulation or other governmental order restrict or limit Tenant's
         use of the Demised Premises, then Tenant
<PAGE>   50
         may cancel this Lease upon written notice to Landlord within ninety
         (90) days following that date upon which Tenant shall have become aware
         of such law, regulation order and thereupon Tenant shall have no
         further obligation to Landlord either hereunder or otherwise. In
         addition, Tenant may use all or any part of the Demised Premises for
         any lawful purpose then permitted by the zoning ordinances and the
         certificate of occupancy.

         Tenant may, if Tenant so elects, and for Tenant's sole use, install and
         operate within the Demised Premises microwave ovens and install and
         operate within the Demised Premises vending machines to dispense hot
         and cold beverages, ice cream, candy, food and cigarettes; such
         machines shall be maintained in a neat and sanitary condition and shall
         comply with all applicable laws and ordinances.


5.       PREPARATION OF PREMISES

         Landlord shall, at Landlord's sole cost and expense perform all work
         and furnish all materials necessary to complete the Demised Premises in
         accordance with Preliminary Plans and Specifications which shall be
         agreed to by Tenant and Landlord. Such plans and specifications shall
         be deemed to be Exhibit B-1, attached hereto and made a part hereof.

         Landlord, using Landlord's Architect and Engineer at Landlord's sole
         cost and expense, shall prepare complete final Architectural and
         Engineering drawings and Specifications (hereinafter referred to as
         "AE&S Drawings") in accordance with those Preliminary Plans and
         Specifications submitted by Tenant and approved, or deemed approved, by
         Landlord. Landlord agrees to make revisions to the AE&S Drawings as
         required by Tenant, at no additional cost to Tenant. The AE&S Drawing
         agreed to by Tenant and Landlord on or before DECEMBER 26, 1991 will be
         the drawings provided to Landlord's General Contractor for the
         construction of the Demised Premises and such drawings shall be deemed
         to be Exhibit C, attached hereto and made a part hereof. Such final
         AE&S drawings shall be stamped, as may be necessary, by a licensed
         Engineer so that Building Permits and/or other required Permits may be
         obtained.

         Landlord shall provide in the Demised Premises, in addition to the
         Tenant Improvements herein described as Exhibit C, the following, all
         in good condition and proper working order:

         1.       Ceiling grid: material and installation.

         2.       Ceiling tile: material only.

         3.       Building standard mini blinds: material and installation, on
                  all exterior and atrium windows.

         4.       Main HVAC System to include on the floor main supply and
                  return ductwork: Branch ducts and diffusers to the space are
                  not included in the shell.

         5.       Lighting installed in accordance with the building standard
                  plan.

         6.       Dry wall, tape and bed the interior of all exterior walls,
                  cores, demising walls, and all columns.

         7.       Provide electrical service to, and a distribution panel in,
                  the Demised Premises.

         9.       Landlord shall provide an allowance towards the purchase and
                  installation of a telephone communication system to include
                  telephone sets, telecommunication wiring and labor to install
                  to be specified by Tenant as detailed in Exhibit B-1, and such
                  allowance shall not exceed $12,000.00.

         10.      Landlord shall provide an allowance towards the purchase and
                  installation of computer network cabling and such allowance
                  shall not exceed S3,000.00.

         12.      Adequate preventive measures so as to eliminate or
                  substantially reduce noise and/or vibration from external
                  sources, such as vehicular or railroad traffic.




<PAGE>   51
         13.      Complete final architectural and engineering drawings and
                  specifications, stamped as may be necessary by a licensed
                  engineer and/or architect so that building and/or other
                  required permits may be obtained.

         Landlord and Tenant acknowledge that Landlord may be performing work in
         the Building simultaneously with Tenant's work, and Landlord and Tenant
         agree to cooperate with each other in the conduct of their work,
         recognizing the amount of space each party will be working on, in terms
         of fairly allocating access to the freight elevator, truck loading dock
         and like facilities.

         If the Premises and Demised Premises are not so completed on or before
         the Scheduled Commencement Date as hereinbefore set forth, then the
         term of this Lease and the obligation of Tenant to pay rent shall not
         commence until the Premises are completed pursuant to the foregoing
         paragraph, and Landlord shall have given Tenant at least
         fifteen(15)days written notice prior to the date the Premises are so
         completed. In the event Landlord fails to so complete the Building and
         the Premises for causes beyond Landlord's control, such as strikes,
         governmental restrictions, and acts of God, then the Commencement Date
         shall be postponed for the period of such delay, provided however, that
         if the Landlord fails to so complete the Premises (for a cause either
         within or beyond Landlord's control) on or before February 1, 1992,
         then Tenant, at Tenants reasonable discretion may cancel this Lease by
         giving written notice to Landlord and thereupon Tenant shall have no
         further obligation to Landlord either hereunder or otherwise.

         In the event the Demised Premises are not completed on or before the
         Commencement Date for the reasons set forth in the preceding paragraph
         permitting postponement of the Commencement Date, then Landlord and
         Tenant promptly shall execute a document in the form attached hereto as
         Exhibit D and made a part hereof, to establish the Commencement Date.
         In the event the delay in the Commencement Date was caused by Tenant,
         then the Expiration date shall be extended for a like period so as to
         provide for the full term as set forth in Paragraph 2 hereof, but in
         the event the delay in the Commencement Date was caused by force
         majeure or by delay by the Landlord, then Tenant shall have the option
         (a) to extend the Expiration Date by a like period so as to provide for
         the full term as set forth in Paragraph 2 hereof, or (b) not to extend
         the Expiration Date.

         Tenant hereby designates JUDY O'REILLY as its representative with
         authority to approve changes in design or construction, and to inspect
         and approve workmanship and material. In all cases, his/her signature
         shall be final and binding upon Tenant with respect to the authority
         herein granted to him/her. All alternates either of additions or
         deletions, agreed to between Landlord and Tenant must be in writing and
         must be agreed to Tenant's representative to be binding. Tenant
         reserves the right to designate an alternate representative by notice
         to Landlord.

         Landlord hereby guarantees that the work shall be free from defects for
         a period of one (1) year from the completion date. Landlord shall at
         Landlord's sole cost and expense, promptly correct any portion of the
         work found to be defective during the one (1) year period, and any
         other portion of the work damaged or destroyed in the course of such
         correction.

         Upon completion and acceptance of the Demised Premises, Landlord shall
         if requested by Tenant at no expense to Tenant furnish Tenant with a
         complete set of "As-Built" drawings setting forth all improvements to
         the Demised Premises.


6.       TELEPHONE EQUIPMENT

         Landlord shall provide suitable non-exclusive space for installation of
         Tenant's telephone relay cabinets, power panels and electric panels.
         Such space will be in addition to the Demised Premises and shall be
         provided at no additional cost to Tenant.


                                       3





<PAGE>   52
7.       MAINTENANCE AND REPAIRS

         Landlord shall, at Landlord's sole expense, maintain and repair the
         Premises and the Building in a first-class condition, with all systems
         properly functioning. Upon notification by Tenant, Landlord shall
         promptly repair any damage to or defect in the Premises and the
         Building; provided however that if such damage is occasioned by fault
         or neglect of the Tenant (except as provided in Paragraph 18 hereof)
         and there shall not be effect at the time such occurred a policy or
         policies of insurance insuring Landlord against any loss resulting from
         such damage, then Tenant shall reimburse Landlord for the cost of
         repairs, or if the proceeds of such insurance are insufficient to cover
         the cost of such repairs, then Tenant shall reimburse Landlord the
         difference between such cost and the proceeds which Landlord received.


8.       ALTERATIONS

         Tenant shall have the right to make such alterations and modifications
         to the Demised Premises as Tenant may deem desirable provided such
         non-structural alterations and modifications do not exceed $5,000.00
         per occurrence. Should Tenant desire to make any alterations or
         modifications which exceed $5,000.00 per occurrence or any structural
         alterations or modifications, then Tenant agrees to first obtain
         Landlord's consent, which consent shall not be unreasonably withheld or
         delayed. Should Landlord fail to respond to Tenant's request within
         five (5) days, the Landlord's consent shall be deemed given. All of
         Tenant's construction to the Demised Premises shall be performed in a
         good and workman like manner in accordance with applicable building
         codes, regulations and all other legal requirements. Any damage to the
         Building resulting from such alterations or modifications shall be
         repaired at Tenant's expense.


9.       SIGNS AND BUILDING NAME

         Tenant at Landlord's expense shall have the right to be listed on the
         Building lobby directory, if any, and to have identification signs
         outside of the Demised Premises, within the Building in conformance
         with Landlord's approved signage plan for the Complex. Tenant at
         Tenant's expense shall have the right to require to be installed and/or
         removed in conformance with Landlord's approved signage plan for the
         Complex, at Tenant's option, an illuminated or nonilluminated sign on
         an exterior wall of the Building, and/or a monument sign, provided such
         sign does not violate any governmental law, ordinance or regulation.


10.      SERVICES

         Landlord shall furnish the following installations and/or services to
         Tenant at Landlord's cost and expense, all of which shall be adequate
         for the intended use of the Premises and in conformity with that
         finished in local first-class buildings of similar nature. These
         services shall be provided between the hours of 7 a.m. to 6 p.m. on
         normal business days, and 9 a.m. to 1 p.m. on Saturdays, except, all
         equipment necessary to operate heating, ventilating and air
         conditioning systems shall be operated sufficiently in advance and
         during these hours so as to provide such services and all cleaning
         services shall be provided before or after such hours.

         (a) Elevator service, with a minimum of one elevator subject to call at
         all times.

         (b) Year round air conditioning system capable of producing and
         maintaining the following conditions throughout the Demised Premises,
         regardless of outside temperature.

                  (i)      Temperature and Humidity - inside temperature to be
                           maintained at:

                           Summer:  74 degrees FDB +/- 2 degrees FDB relative 
                                            humidity 50% maximum.
<PAGE>   53
                           Winter:  72 degrees FDB +/- 2 degrees FDB relative 
                                            humidity 25% minimum.


                                        4
<PAGE>   54
                  (ii)     Temperature Control - areas having excessive heat
                           gain or heat loss or are affected by solar radiation
                           at different times of the day shall be independently
                           zoned and controlled so that the interior temperature
                           condition stipulated above can be maintained.

                  (iii)    Air Movement - in conference rooms and toilet areas,
                           a mechanical ventral system shall be furnished to
                           provide for the exhausting of stale air and smoke as
                           well as providing a comfortable circulation of air.

                  (iv)     Drafts, Noise and Vibration - the heating, air
                           conditioning and ventilating systems shall be free
                           from objectionable drafts, noise and vibration.

                  (v)      Filtration - all air conditioned supply air shall be
                           adequately filtered so as to maintain a clean, dust
                           free, non-toxic and odorless environment.

                  (vi)     Ventilation - the air conditioning system shall
                           supply not less than 25% of fresh air while in
                           operation. In toilets exhaust air quantities of at
                           least 50 cu. ft./minute for each water closet or
                           urinal or 2 cu. ft. per square foot of floor area,
                           whichever is greater, is to be provided.

                  (vii)    Service and maintain an existing stand alone air
                           conditioner in the Demised Premises commonly known as
                           a CONTEMPO unit.

         (c)      All utility services. In addition, Landlord shall furnish, at
                  its sole cost and expense, all necessary utilities including
                  electricity, to the exterior common areas, including the
                  walkways, driveways and parking area.

         (d)      Adequate insect and vermin control.


         (e)      Adequate security services for the Premises and the Building
                  including fire and burglar alarm devices.

         (f)      Initial or first installation of lamps and/or bulbs as well as
                  future replacement, as required, of lamps and/or bulbs,
                  ballasts and starters to maintain a light level of 75 foot
                  candles at desk level.

         (g)      Landlord acknowledges that the availability of sufficient
                  parking is a material inducement to the entering into of this
                  Lease by Tenant. Landlord represents that it has sufficient
                  parking available to provide at no cost to Tenant and for
                  Tenant's exclusive use at least 3.9 paved parking spaces for
                  every 1,000 rentable square feet in the Demised Premises of
                  which 2 spaces shall be in the open parking area and shall be
                  marked exclusive to Tenant, all of which shall be no more than
                  100 feet from any public entrance to the Building. There shall
                  be a minimum of 350 square feet allocated for each parking
                  space including aisle and turnaround space.

         (i)      Landlord shall provide, at no expense to Tenant, cleaning
                  service, trash removal, and window washing for the Demised
                  Premises and the Premises in accordance with the Cleaning
                  Schedule marked Exhibit E and attached hereto and made a part
                  hereof.

         Tenant acknowledges that any one or more of the services provided for
         in Paragraph 10 hereof may be interrupted or suspended by reason of
         accident, repair, alterations or improvements necessary to be made,
         strikes, lockout, and except as hereinafter provided, Landlord shall
         not be liable to Tenant therefore, provided however, that (a) Landlord
         shall use its best efforts to restore such services as soon as
         reasonably possible, (b) in the event such services is not restored
         within ten (10) business days, whether or not through the fault of
         Landlord, to the extent that 
<PAGE>   55
         Tenant cannot reasonably use all or any part of the Premises rent and
         other charges shall abate as to such part effective on the eleventh
         (11) business day and continue abated until such service is restored,
         and (c) in the event such interruption continues for thirty (30)
         calendar days, whether or not through the fault of Landlord, then
         Tenant shall have the right and option to cancel and terminate this
         Lease, on ten (10) days written notice to Landlord, and thereafter
         shall be relieved of all further liability under this Lease.


                                        5
<PAGE>   56
11.      REDECORATING
         DELETED IN ITS ENTIRETY


12.      COMPLIANCE WITH LAW

         Landlord covenants that the Demised Premises, the Premises and the
         Building, and the fixtures and appurtenances thereto (except those
         installed by Tenant) do conform or that Landlord will promptly cause
         them to conform to every applicable requirement of law or duly
         constituted authority or the requirements of the carriers of all
         insurance on or relating to the Demised Premises, the Premises or the
         Building whether such insurance be furnished by Landlord or Tenant and
         that Landlord will, at its sole risk and expense, at all times during
         the term hereof promptly comply with all such requirements. The Tenant
         shall comply with all applicable statutes, ordinances, rules and
         regulations of federal, state and municipal governments and all
         applicable rules and regulations of the Board of Fire Underwriters as
         such statutes, ordinances, rules and regulations pertain to Tenant's
         use of the Demised Premises.

         Landlord shall also comply with all applicable city, county, state and
         federal ordinances in effect from time to time with respect to
         facilities for the handicapped in the Demised Premises, the Premises
         and the Building.


13.      LANDLORD'S TITLE, AUTHORITY AND QUIET ENJOYMENT

         Landlord covenants and represents that it has good and marketable title
         to the Building and the Complex, free and clear of all ground leases,
         liens and mortgages or deeds of trust affecting Tenant's possession of
         the Demised Premises, Tenants use of the Premises, or the rights
         granted to Tenant hereunder, except: a mortgage/deed of trust dated Nov
         2, 1987 from Landlord, as mortgagor, and NEW ENGLAND MUTUAL LIFE
         INSURANCE COMPANY, A MASSACHUSETTS CORPORATION, as
         mortgagee/beneficiary of deed of trust.

         In the event this Lease or the leasehold estate created hereunder is
         subject to the prior rights of any mortgagee/beneficiary of deed of
         trust or ground lessor, then Landlord shall secure from such
         mortgage/beneficiary of deed of trust or ground lessor a written
         agreement in recordable form, in the form of Exhibit 'F',
         Non-Disturbance and Attornment Agreement (executed and acknowledged by
         and on behalf of such mortgagee/beneficiary of deed of trust, or ground
         lessor), which provides, among other kings that Tenant, so long as
         Tenant is not in default hereunder, may remain in possession of the
         Demised Premises pursuant to the terms hereof and without diminution of
         Tenant's rights should Landlord become in default with respect to such
         mortgage or ground lease or should the Premises become the subject of
         any action to foreclose any mortgage or to dispossess Landlord. Such
         agreement shall be secured and furnished to Tenant at the same time
         this executed Lease is delivered to Tenant.

         Landlord covenants and represents that it has full and complete
         authority to enter into this Lease under all of the terms, conditions
         and provisions set forth herein, and so long as Tenant keeps and
         substantially performs each and every term, provision and condition
         herein contained on the part of Tenant to be kept and performed, Tenant
         shall peacefully and quietly enjoy the Premises without hindrance or
         molestation by Landlord or by any other person claiming by, through or
         under Landlord.



14.      SUBORDINATION

         The priority of this Lease and the leasehold estate of Tenant created
         hereunder are and shall be subject and subordinate to the lien of any
         mortgage or ground lease, whether such mortgage is placed against the
         fee or leasehold estate, which may now 
<PAGE>   57
         or hereafter affect the Building to all renewals, modifications,
         consolidations, replacements and extensions thereof, and advances
         thereunder, effective upon the date the mortgagee or ground lessor, as
         the case may be, shall deliver to Tenant a written agreement in the
         form of Exhibit "F", Non-Disturbance and Attornment


                                        6
<PAGE>   58
         Agreement (executed and acknowledged by and on behalf of the
         mortgagee/beneficiary, of deed of trust, or ground lessor) in
         recordable form which provides, among other things that Tenant, so long
         as Tenant is not in default hereunder, may remain in possession of the
         Demised Premises pursuant to the terms hereof and without any
         diminution of the Tenant's rights should Landlord become in default
         with respect to such mortgage or ground lease or should the Premises
         become the subject to of any action to foreclose any mortgage or to
         dispossess Landlord. Any fee which Landlord's lender or ground lessor
         may charge for such agreement shall be paid by Landlord.


15.      ASSIGNMENT AND SUBLETTING

         Tenant shall have the right to assign this Lease or to sublease all or
         any portion of the Demised Premises, with Landlords, consent which
         consent shall not be unreasonably withheld or delayed. Should Landlord
         fail to respond to Tenant's request within five (5) days Landlord's
         consent shall be deemed given. Any such assignment or subletting shall
         not relieve Tenant of its obligations hereunder.

         In the event Tenant sells the operating unit which occupies the Demised
         Premises to another company, then anything to the contrary in this
         paragraph notwithstanding, Tenant shall have the right to assign this
         Lease to such other company, but Tenant shall not thereby be released
         liability under this Lease.


16.      LEASE EXTENSION

         If this Lease shall not have been terminated pursuant to any provisions
         hereof and Tenant is not in default under the terms hereunder, then
         Tenant may, at Tenant's option, extend the term of this Lease for one
         (1) successive additional term of three (3) year, commencing on the
         expiration of the original term, or the immediately preceding
         additional term as the case may be, and in the event Tenant has elected
         to exercise its option to lease additional space pursuant to Paragraph
         25 the option provided for herein shall include such additional space.
         At least nine (9) months prior to the expiration of the initial term or
         any extended term, as the case may be, Tenant shall request from
         Landlord the fair market rental rate being charmed in the Building,
         should Tenant desire to extend the term of this Lease. At least eight
         (8) months prior to the expiration of the initial or any extended term
         Landlord shall notify Tenant, in writing, the applicable rental rate
         for the next succeeding option period. Tenant may exercise such option
         by giving Landlord written ,notice by the date which is the later to
         occur of (a) six (6) months prior to the expiration of the original
         term or the additional term, as the case may be, and (b) sixty (60)
         days after receipt by Tenant of Landlord's notice of the applicable
         rental rate, as herein above and (c) fifteen (15) days after the fair
         market rental rate has been determined arbitration. Upon the giving by
         Tenant to Landlord of such written notice and the compliance by of
         Landlord and Tenant with the foregoing provisions of this Paragraph 16,
         the term his Lease shall by deemed to be automatically extended upon is
         the covenants, agreements, terms, provisions and conditions, set forth
         in this Lease, except rental which

         (a)      During the first renewal term shall be limited to a maximum of
                  90% of the then fair market rental rate,

         (b)      Or if Tenant elects, the rental rate schedule shall be as
                  follows:

                  $1.65 per rentable square foot for months 36 through 48,
                  $1.70 per rentable square foot for months 49 through 60,
                  $1.75 per rentable square foot for months 61 through 72,

         (c)      Upon execution of this extension option, Landlord shall
                  repaint the Demised Premises with two (2) coats of prime
                  quality paint; repainting shall be performed in a workmanlike
                  manner with a minimum of interference with Tenant's normal
                  business operations and replace all carpeting, with a quality
                  comparable to the initial installation, in the Demised
                  Premises and in any adjoining lobby/reception area, and

         except for such terms and conditions as shall be inapplicable during
         any additional term or in connection with this Paragraph 16.


                                        7
<PAGE>   59
         The term "month" as used in this paragraph shall mean (a) if the
         Expiration Date is the last day of a calendar month, a calendar month,
         or (b) if the Expiration Date is not the last day of a calendar month,
         the period between the Expiration Date and the date in the preceding
         month which is one (1) day after the date in the month of the
         Expiration Date, e.g., if the Expiration Date falls on May 19, one (1)
         "month" prior thereto would be April 20 and two (2) 'months' prior
         thereto would be March 20.

         With respect to the lease extensions, the applicable 'fair market
         rental rate' shall be that rate charged for space of comparable size
         and condition in comparable buildings, including the Building, located
         in the geography commonly known as the Golden Triangle area of the City
         of San Diego, taking into consideration the location, quality and age
         of the building, floor level, extent of leasehold improvements
         (existing or to be provided) including the amount spent by Tenant for
         leasehold improvements over building standard in the Demised Premises,
         rental abatements, lease takeover/assumptions, moving expenses and
         other concessions, term of lease, extent of services to be provided,
         distinction between "gross" and "net" lease, a base year or amount for
         escalation purposes "both operating costs and ad valorem/real estate
         taxes" and the time the particular rental rate under consideration
         becomes or is to become effective, or any other relevant term or
         condition, including any allowances for leasehold improvements, thus,
         the "fair market value" rental rate may be a dental rate with or
         without an allowance and/or with or without various other concessions
         as set forth hereinabove.

         In the event Tenant disagrees with Landlord's determination of the fair
         market rental rate. Tenant shall promptly so notify Landlord and
         Landlord and Tenant shall thereupon negotiate in good faith to attempt
         agree upon a mutually acceptable fair market rental rate, but in the
         event agreement has not been reached within thirty (30) days after
         Tenant's receipt of Landlord's Notice, then Tenant shall have the
         option to demand arbitration as provided in Paragraph 46 hereof.

         If Tenant fails or omits to so give to Landlord the first written
         notice referred to above, it shall be deemed, without further notice
         and without further agreement between the parties hereto, that Tenant
         elected not to exercise the options granted Tenant pursuant to this
         Paragraph 16 to extend the term of this Lease for additional periods.

17.      TAXES, ETC.

         Landlord shall pay all real estate taxes, assessments, water and sewer
         rates and charges, and any other charges which may be levied, assessed
         or charged against the payments to be Building and/or the Complex.
         Landlord further make al require made under the terms of any mortgage
         or deed of trust or ground lease which is now or hereafter a lien on
         the Building or the Complex which is superior to this Lease and all
         payments required to be made under any ground lease. Landlord shall
         have a reasonable time to cure a default under the terms of the
         mortgage or deed of trust, before constituting an event of default by
         Landlord as hereinafter described in Paragraph 23 of this Lease.


18.      INSURANCE AND WAIVER OF LIABILITY

         Landlord shall provide, at its expense, throughout the term of the
         Lease, comprehensive general liability insurance covering the Building
         and the Premises, except when caused by the sole or Tenant's failure to
         perform its obligations under this Lease evidencing such insurance
         shall provide that same may not be without fifteen (15) days. prior
         written notice to Tenant, and shall provide for a combined coverage of
         bodily injury and property damage in an amount not less than Five
         Million Dollars ($5,000,000). Such policy or policies shall be issued
         by an insurance company licensed to do business in the state in which
         the Building is situate. Upon Tenant's request, Landlord shall summit
         to Tenant suitable evidence that the foregoing policy or policies are
         in effect. Tenant shall provide, at its expense, throughout the term of
         this Lease, comprehensive general liability insurance covering the
         Building and the Premises when caused by the sole negligence of Tenant
         or Tenants failure to perform its obligations under this Lease. The
         policy or policies evidencing such insurance shall provide that same
         may not be cancelled or amended without fifteen (15) days prior written
         notice to Landlord,


                                        8
<PAGE>   60
         and shall provide for a combined coverage of bodily injury and property
         damage in an amount not less than Five Million Dollars ($5,000,000).
         Such policy or policy shall be issued by an insurance company licensed
         to do business in the state in which the Building is situate. Upon
         Landlord's request, Tenant shall submit to Landlord suitable evidence
         that the foregoing policy or policies are in effect. Notwithstanding
         the foregoing, Tenant may insure the foregoing risks under its blanket
         policy, or elect to self-insure such risks.

         Landlord, for itself and its insurers, hereby releases Tenant with
         respect to any liability (including that deriving from the fault or
         neglect of Tenant, assignee, subtenants, its agents, employees or other
         persons under its or their direction or control) which Tenant might
         otherwise have for any damage to the Building or the Demised Premises
         by fire, other casualty or cause which Landlord could have covered by a
         standard fire insurance policy with extended coverage endorsement. The
         term "Tenant" as used in this paragraph shall include any subsidiary of
         Tenant and any assignee or subtenant of Tenant.

         Landlord shall insure the Building against fire or other casualty with
         extended coverage endorsement with an insurance company selected by
         Landlord and Landlord shall cause the policy evidencing such insurance
         to include a provision permitting such release of liability if such a
         provision is obtainable from such insurer at no additional expense to
         Landlord. If such insurer will not include such a provision in such
         policy, or if the inclusion of such provision in such policy would
         involve an additional expense for Landlord, Landlord shall so notify
         Tenant within a reasonable time. Where such a provision is obtainable
         from such insurer and Tenant notifies Landlord in writing within a
         reasonable time thereafter that Tenant desires Landlord to cause such a
         provision to be included in such policy at the expense of Tenant,
         Landlord shall cause such a provision to be included, and Tenant agrees
         to pay promptly all expenses incurred by Landlord as a result of such
         inclusion.


19.      DAMAGE

         In the event that the Building or Premises are damaged for any reason
         whatsoever and Tenant is unable, in Tenants reasonable business
         judgement, to carry on its normal business operations for a period of
         forty five (45) days or more, Tenant shall have the right to terminate
         this Lease by giving written notice of such termination to the Landlord
         no later than thirty (30) days after the occurrence of such damage.
         Upon such termination, Tenant's obligations hereunder and each of them,
         including the obligation to pay rent, shall cease and determine as of
         the day the Premises were so damaged. If in Tenant's reasonable
         business judgement, it is unable to carry on its normal business
         operations for a period of less than forty five (45) days because of
         such damage, rent shall abate (or any free rent period provided for in
         Paragraph 3 hereof shall be extended) for the period the Premises are
         untenantable.

         In the event the Premises are partially damaged by fire or other
         casualty and Tenant shall determine that it is able to carry on its
         normal business operations, Tenant shall pay rent for only such portion
         of the Premises which Tenant in its determination may reasonably occupy
         during the time required to make repairs. All repairs necessary to
         restore the Premises to its original condition shall be:

         (a)      commenced within thirty (30) days after the occurrence of such
                  damage;

         (b)      performed in a diligent and workmanlike manner with material
                  of at least the same quality utilized originally in the
                  construction of the Premises;

         (c)      completed by Landlord at Landlord's sole expense with a
                  minimum of interference with Tenant's normal business
                  operations.

         If in Tenant's determination Landlord shall not have performed any of
         the above obligations in strict compliance therewith, then Tenant may,
         but shall not be requited to, undertake such obligations, and all costs
         and expenses incurred by Tenant as a result thereof may be deducted
         from any rent or other payment clue or to become due hereunder.


                                        9
<PAGE>   61
20.      CONDEMNATION

         In the event the Building or the Complex shall be condemned for public
         use or voluntarily transferred to a public or quasi-public body in lieu
         of proceeding to a judgment of condemnation, this Lease shall terminate
         any rent shall be adjusted to the date of termination. In the event a
         portion of the Building or the Complex shall be condemned for public
         use or voluntarily transferred to a quasi-public by of proceeding to a
         judgment of condemnation and Tenant is unable, in Tenant's reasonable
         business judgement, to carry on its normal business operator. A period
         of forty five (45) days or more, Tenant shall have the right to
         terminate giving written notice of such termination to the Landlord no
         later than thirty (30) days after the occurrence of such condemnation
         or transferal. Upon such a termination, Tenant's obligations hereunder
         and each of them, including the obligation to pay rent, shall cease and
         determine as of the date of termination. If in Tenant's determination,
         it is unable to carry on its normal business operations for a period of
         less than forty five (45) days because of such partial condemnation,
         rent shall abate for the period the Premises are untenantable.

         In the event a portion of the Building or Complex shall be condemned
         for public use or voluntarily transferred to a public or quasi-public
         body in lieu of proceeding to a judgment of condemnation, and Tenant
         shall determine that it is able to carry on its normal business
         operations, Tenant shall pay rent for only such portion which Tenant in
         its determination may reasonably occupy after such partial condemnation
         or transfer. All repairs necessary to restore the Demised Premises,
         Premises, Building or the Complex as nearly as possible to its original
         condition shall be:

         (a)      commenced within thirty (30) days after the taking or
                  transfer;

         (b)      performed in a diligent and workmanlike manner with material
                  of at least the same quality utilized originally in the
                  construction of the Building or Complex.

         (c)      completed by Landlord at Landlord's sole expense with a
                  minimum of interference with Tenant's normal business
                  operations.

         If in Tenant's determination Landlord shall not have performed any of
         the above obligations in strict compliance therewith, then Tenant may,
         but shall not be required to, undertake such obligations, and all costs
         and expenses incurred by Tenant as a result thereof may be deducted
         from any rent or other payment due or to become due hereunder. Tenant
         is hereby granted a lien upon any award or settlement resulting from
         the condemnation to the extent that Tenant has not been reimbursed for
         any cost or expense which Tenant may have incurred hereunder.

         Except as provided in the paragraph immediately preceding, Tenant shall
         not be entitled to any award or settlement resulting from the
         condemnation, provided that nothing contained herein shall be construed
         to in any way restrict or limit Tenant from asserting a claim for any
         damages resulting from the taking of any leasehold improvements paid
         for by Tenant or moving expenses incurred as a result of such
         condemnation.

21.       DEFAULT BY TENANT


         The occurrence of any one or more of the following events shall
         constitute an event of default by Tenant:

         (a)      the failure by Tenant to make any payment of rent or any other
                  payment required to be made by Tenant hereunder, as and when
                  due, where such failure shall continue for a period of ten
                  (10) days after receipt of written notice thereof by Tenant
                  from Landlord;

         (b)      the failure by Tenant to observe or perform and of the
                  covenants, conditions or provisions of this Lease where such
                  failure shall continue for a period of thirty (30) days after
                  receipt of written notice thereof by Tenant from Landlord,
                  provided however that if the nature of Tenant's default is
                  such that 
<PAGE>   62
                  it cannot be cured solely by payment of money and that more
                  than thirty (30) days may be reasonably required for such
                  cure, then Tenant shall not be deemed to be in default if
                  Tenant shall commence such cure within such thirty (30) day
                  period and shall thereafter diligently prosecute such cure to
                  completion;


                                       10
<PAGE>   63
         (c)      (i)      the making of any general arrangement or any
                           assignment by Tenant for the benefit of creditors;

                  (ii)     the filing by or against Tenant of a petition to have
                           Tenant adjudged a bankrupt or a petition of
                           reorganization or arrangement under any law relating
                           to bankruptcy (unless in the case of a petition filed
                           against Tenant, when such petition is dismissed
                           within ninety (90) days);

                  (iii)    the appointment of a trustee or receiver to take
                           possession of substantially all of Tenant's assets;

                  (iv)     the attachment, execution or other judicial seizure
                           of substantially all of Tenant's assets.


22.      LANDLORDS REMEDIES

         Upon the occurrence of an event of default under this Lease by Tenant,
         then Landlord in addition to other rights or remedies it may have,
         shall have the right to terminate this Lease upon fifteen (15) days
         written notice to Tenant, and also the right, with or without
         termination of this Lease, of reentry upon and taking possession of the
         Demised Premises and Landlord may remove all persons and property from
         the Demised Premises; such property may be removed and stored in any
         other place in the Building or in any other reasonably secure place for
         the account of and at the expense and risk of Tenant. Tenant hereby
         waives all claims for damages which may be caused by the reentry of
         Landlord and taking possession of the Demised Premises or removing or
         storing the furniture and property as herein provided and shall save
         Landlord harmless from any costs or damages occasioned Landlord
         thereby, and no such reentry shall be considered or be construed to be
         a forcible entry. Should Landlord elect to reenter, as herein provided,
         or should it take possession pursuant to legal proceedings or pursuant
         to any notice provided for by law, Landlord may either terminate this
         Lease or, Landlord may from time to time, without terminating this
         Lease, relet the Demised Premises or any part thereof for such term or
         terms and at such rental or rentals and upon such other terms and
         conditions as may be reasonable, with the right to make minor
         alterations and repairs to the Demised Premises. Rental received by
         Landlord from such reletting shall be applied first, to the payment of
         any costs of such relettinq including reasonable brokerage and
         attorney's fee; and the residue, if any, shall be-held by Landlord and
         applied in payment of future rent as the same may become due and
         payable hereunder. Should such rentals received from such relenting
         during any month be less than one-twelfth (1/12) of the annual rent
         reserved hereunder, then Tenant shall pay such deficiency to Landlord.
         Such deficiency shall be calculated and paid monthly. No such reentry
         or taking possession of the Demised Premises by Landlord shall be
         construed as an election on its part to terminate this Lease, unless
         written notice of such intention be given to Tenant, in which event
         Tenant's obligations to Landlord shall forthwith cease, or unless the
         termination thereof be decreed by a court of competent jurisdiction.


23.      DEFAULT BY LANDLORD

         The occurrence of any one or more of the following events shall
         constitute an event of default by Landlord:

         (a)      The failure by Landlord to make any payment required to be
                  made by Landlord hereunder, as and when due, where such
                  failure shall continue for a period of ten (10)days after
                  receipt of written notice thereof from Tenant to Landlord;

         (b)      The failure by Landlord to observe or perform any of the
                  covenants, conditions or provisions of this Lease where such
                  failure shall continue for a period of thirty (30) days after
                  receipt of written notice thereof from Tenant to Landlord;
                  provided however, that if the nature of Landlord's default is
                  such that it cannot be cured solely by payment of money and
                  that more than thirty (30) days may be reasonably required for
                  such cure, then Landlord shall not be deemed to be in default
                  if Landlord shall commence such cure within such 
<PAGE>   64
                  thirty (30) day period and shall thereafter diligently
                  prosecute such cure to completion.


                                       11
<PAGE>   65
24.      TENANT'S REMEDIES

         Upon the occurrence of an event of default under this Lease by
         Landlord, then Tenant in addition to other rights or remedies it may
         have, at Tenant's sole option, may set off any amount owed to Tenant by
         Landlord against any rent or other payment due or to become due
         hereunder or perform any obligations of Landlord (which Landlord has
         failed to perform) in which event Tenant shall have the right to set
         off any expense incurred thereby against any rent or other payment due
         or to become due hereunder.


25.      ADDITIONAL SPACE

         Landlord hereby grants to Tenant the right to lease additional space
         contiguous to the Demised Premises and any other location in Building 1
         upon the following terms and conditions:

         (a)      No later than four (4) months prior to the time additional
                  space in Building I by Tenant, Tenant shall notify Landlord in
                  writing that Tenant elects to exercise this right.

         (b)      Within fifteen (15) days after Landlord receives such notice,
                  Landlord shall inform Tenant in writing the exact date
                  additional space shall be available for preparation by Tenant.
                  Provided that Tenant exercises this right Between months 1 and
                  12 inclusive of this original Term Landlord agrees to
                  contribute toward the preparation of additional space the same
                  sum of dollars per rentable square foot as was required
                  buildout Tenant's original improvements multiplied by the
                  number of additional rentable square feet. If however, Tenant
                  exercises this right between months 13 and 36 inclusive of
                  this original Term, Landlord agrees to only perform touch-up
                  painting and carpet cleaning for any additional rentable
                  square feet to be leased. All improvements required to be made
                  hereunder shall be of the same and/or similar quality required
                  to be furnished with respect to the completion of the Demised
                  Premises.

         (c)      The rent for any additional space shall be computed at the
                  same annual rate per square foot as the rent for the space
                  described in Paragraph 1 hereof and shall commence on the date
                  the additional space has been completed in accordance with (b)
                  above as the case may be.

         (h)      The term of the Lease for such additional space shall be the
                  balance of the term of this Lease and any additional term
                  thereof.

         (i)      Landlord shall provide Tenant with additional parking spaces
                  in the event Tenant elects to lease additional space in the
                  same ratio set forth in Paragraph 10 (h).

         (j)      All of the terms and conditions of this Lease not inconsistent
                  with this Paragraph 25 shall govern the leasing of any
                  additional space.

         (k)      Any space added to the Demised Premises pursuant to this
                  Paragraph 25 shall thereafter be deemed to be a part of and
                  included in the Demised Premises.


26.      DOWNSIZE AND RETURN OF SPACE
         DELETED IN ITS ENTIRETY

27.      RIGHT OF FIRST REFUSAL TO PURCHASE
         DELETED IN ITS ENTIRETY


                                       12
<PAGE>   66
28.      FIRST RIGHT TO LEASE

         If, during the original or any additional term hereof, Landlord elects
         to lease any space in Building 2 of Governor Park Plaza, 6363 Greenwich
         Drive, then Landlord shall first offer such space in writing to Tenant
         on terms and conditions no less favorable than those offered to third
         parties. If within twelve (12) days after receipt of such offer, Tenant
         does not notify Landlord that Tenant elects to lease such space, then
         Landlord shall be relieved of any obligations to Tenant with regard to
         any such offering; provided, however that a failure by Tenant to lease
         any specific space when so offered by Landlord shall not relieve
         Landlord of its obligation to first offer Tenant any other space in
         Building 2 if, as and when Landlord elects to offer such other space to
         third parties.


29.      RENT ABATEMENT

         Should Tenant or those holding by, through or under Tenant not occupy
         all or any portion of the Demised Premises for any period during the
         term hereof or any additional term for any reason whatsoever, then
         anything herein to the contrary notwithstanding, Landlord and Tenant
         shall mutually agree to the percentage of the monthly rent for which
         Tenant is or might be obligated to pay based on the previous 6 month
         Operating Expense history for the Complex, and which the parties a
         agree constitutes the cost of providing the services set forth in
         Paragraph 10 shall abate for as long as that portion of the Demised
         Premises are not so occupied.


30.      DELIVERY OF EXECUTED LEASE AND RELATED DOCUMENTS

         Within fifteen (15) days after Tenant delivers to Landlord four (4)
         duplicate originals of this Lease duly executed by Tenant, Landlord
         shall deliver to Tenant two (2) fully executed originals of this Lease
         accompanied by agreements in the Form of Exhibit "F" (Non-Disturbance
         and Attornment Agreement) duly executed and acknowledged by and on
         behalf of each mortgagee/beneficiary of deed of trust referred to in
         Paragraph 13 hereof, and if requested Tenant a Memorandum of Lease in
         the form of Exhibit "G" duly executed and acknowledged by and on behalf
         of Landlord (said executed Lease, Non-Disturbance Agreement(s) and
         Memorandum of Lease are together referred to herein as the "Lease and
         Related Documents"). In the event Landlord shall fail to deliver the
         fully executed Lease and Related Documents as herein required, Tenant
         may, if Tenant so elects, withdraw its execution and delivery of this
         Lease by giving Landlord written notice of such withdrawal. Upon such
         withdrawal neither party shall have any rights against the other either
         hereunder or otherwise except that Landlord shall forthwith return to
         Tenant any sums which Tenant shall have paid to Landlord prior to such
         withdrawal.


31.      TERMINATION

         Landlord hereby grants to Tenant the right to terminate this Lease at
         any time during the initial term upon one hundred and eighty (180) days
         prior written notice to Landlord. In the event Tenant elects to
         terminate the Lease as herein provided, Tenant shall pay to Landlord an
         amount equal to thirty-five percent (35%) of the annual rental set
         forth in Paragraph 3 hereof (as it may have been amended by Paragraphs
         16, 25 and 26 hereof) from the date of termination through the balance
         of the unexpired term of the Lease. Such payment shall be made on or
         before the date such termination becomes effective.


32.      COMPETITORS OF TENANT
         DELETED IN ITS ENTIRETY


                                       13
<PAGE>   67
33.      NOTICES


         All notices shall be sent U.S. Registered Mail, Return Receipt
         Requested to the following addresses:

         TO LANDLORD:                     TO TENANT:

         Governor Park Associates         Xerox Corporation
         c/o Nexus Development Corp.      Attention: RE/GSD Lease Administration
         6333 Greenwich Dr., Ste. 110     800 Long Ridge Road
         San Diego, CA 92122              P.O. Box 1600
                                          Stamford, Connecticut 06904

                                          WITH A COPY TO:

                                          Xerox Corporation
                                          Attention: Manager,
                                          Real Estate Operations
                                          Western United States
                                          1851 E. 1st St., Ste. 460
                                          Santa Ana, CA 92705

         Any notice shall be deemed to have been given on the date set forth on
         the Registry Receipt given to the sender at the time of mailing, except
         that for purpose of Paragraphs 21 and 23 hereof, such notice shall be
         deemed to have been received on the earlier of (a) the date set forth
         on the Return Receipt, (b) the date of delivery as shown on the Post
         Office records, or (c) the date delivery was refused as shown on the
         Post Office records.

         Except as otherwise provided in this Lease, all correspondence to
         Tenant with respect to this Lease or any of the provisions hereof shall
         be sent to the addresses of Tenant set forth above, and any and all
         correspondence sent to Tenant at the Demised Premises or any location
         other than as stated herein, and any documents signed by Tenant at the
         Demised Premises as a result thereof shall be null and void and of no
         force and effect. Either party, by notice to the other, shall have the
         right to change the address(es) for notice(s) to be sent to such party,
         and to add or substitute entities to which a copy of any notice shall
         be sent by the other party.


34.      BROKERAGE

         Landlord and Tenant acknowledge that Mr. J. Wright, of Iliff-Thorn and
         Company is the real estate broker which brought about this lease
         transaction, and Landlord shall pay the brokerage commission to such
         broker pursuant to separate agreement. Landlord hereby indemnifies
         Tenant against the claims of any broker arising from Landlord's acts,
         and Tenant hereby indemnifies landlord against the claims of any other
         broker arising from Tenant's acts.

35.      ESTOPPEL CERTIFICATE

         Landlord and Tenant shall, at any time upon not less than twenty (20)
         days prior written notice, execute and deliver to a prospective new
         landlord, lender, or assignee or subtenant of Tenant, as the case may
         be, a statement in writing (I) certifying that this Lease is unmodified
         and in full force and effect (or if modified, stating the nature of
         such modification and certifying that this Lease, as so modified, is in
         full force and effect), (ii the date to which the rent and other
         charges are paid in advance, if any, and (iii) acknowledging that there
         are not, to the party's knowledge, any uncured defaults or unfulfilled
         obligations on the part of the other party hereunder, or specifying
         such defaults or unfulfilled obligations if any are claimed.


                                       14
<PAGE>   68
36.      INDUSTRIAL DEVELOPMENT BONDS

         Landlord covenants, warrants and represents that tax exempt Industrial
         Development Bonds, sometimes referred to as Industrial Revenue Bonds
         ("I.R.B.s") were not used in financing the Complex or the Building. If
         it is subsequently determined that tax exempt I.R.B.s were used in such
         financing, Tenant shall have the right and option to terminate this
         Lease and thereafter be relieved of all further liability hereunder.

         In the event Landlord Weds to finance the Complex or Building with tax
         exempt I.R.B.s during the term (or any additional term) of this Lease
         and Tenant occupies ten percent (10%) or more of the Building or
         Complex, then Landlord shall promptly so notify Tenant and Landlord
         hereby indemnities and holds Tenant harmless from any loss by or claim
         against Tenant as a result of such tax exempt I.R.B. financing, and
         Landlord hereby releases Tenant from any liability to Landlord as a
         result of such tax exempt I.R.B. financing. In addition, Tenant shall
         have the right and option to terminate this Lease, as herein above
         provided.


37.      ASBESTOS AND CONTAMINATION

         Landlord covenants, warrants and represents that the Premises and the
         Building are free of any friable asbestos containing materials and that
         any non-friable asbestos containing materials in the Premises & the
         Building are identified in Exhibit ___ attached hereto.

         Landlord covenants, warrants and represents that to the best of its
         knowledge after thorough investigation, the Premises and the Building
         (including the land the under) do not contain any environmental
         contaminants ("toxic contamination") of any kind (including PCBs,
         except for PCBs that are totally contained within light fixtures and
         exterior transformers). At any time during the term of this Lease,
         Tenant shall have the right and option, at Tenants expense, to
         investigate the Building for the presence of asbestos and PCBs and to
         investigate the land for the presence of toxic contamination.

         Landlord agrees to indemnify and hold Tenant harmless from any claims
         or actions related to or arising out of any subsequent discovery of
         friable asbestos or toxic contamination at the Premises or the Building
         (including the land thereunder). In the event of such a finding, or in
         the event of any breach of a covenant, warranty or representation by
         Landlord under this paragraph, Tenant shall have the option of
         terminating this Lease without penalty of any kind and be released from
         any liability under the Lease after the date of such termination.


38.      HOLDOVER

         If Tenant shall remain in possession of the Demised Premises after
         expiration of the original or any additional term hereof, Tenant's
         occupancy shall be a month-to-month tenancy at 1.25 times the rental
         rate applicable to the last month of the unexpired term and under all
         of the other terms, conditions and provisions hereof except those
         Retaining to the term of the Lease. Landlord hereby grants to Tenant
         the right to holdover for up to three (3) months.


39.      SURRENDER

         Upon any termination or expiration of this Lease, Tenant shall
         surrender the Demised Premises in the same condition as existed at the
         commencement of the term, except for normal wear and tear and damage
         caused by the elements, casualty, or any other cause for which Tenant
         night not be liable, provided, however, that Tenant shall have the
         option, but not the obligation, to remove any or all of the
         improvements and alterations made to the Demised Premises by Tenant or
         at Tenant's expense. Any damage to the Demised Premises result of such
         improvements or alterations shall be repaired by Tenant at Tenant's
         expense.


                                       15
<PAGE>   69
40.      ROOF-TOP ANTENNA
         DELETED IN ITS ENTIRETY


41.      MODIFICATION OF LEASE

         The terms, covenants and conditions of this Lease may not be changed
         orally but only by an instrument in writing signed by the party against
         whom enforcement of the change is sought. The failure of either party
         hereto to insist in any on or more cases upon the strict performance of
         any term, covenant or condition of this Lease to be performed or
         observed by the other party hereto shall not constitute a waiver or
         relinquishment for the future of any such term, covenant or condition.


42.      MEMORANDUM OF LEASE

         Neither party shall record this Lease or any of the exhibits and/or
         riders attached hereto, (except that Tenant may record the executed
         Non-Disturbance and Attornment Agreement) but at the request of either
         party, Landlord and Tenant shall enter into a 'short form' or
         Memorandum of Lease in recordable form, attached hereto as Exhibit 'G'
         and made a part hereof, which may be recorded and which shall set forth
         the parties, the legal description of the land underlying the Building
         or Complex, a description of the Demised Premises, the Commencement
         Date and Expiration Date of the term of the Lease, and any options
         and/or restrictions in this Lease cleared to be included by either
         party.


43.      PARAGRAPH CAPTIONS

         Paragraph captions herein are for Landlord's and Tenant's convenience
         only, and neither limit nor amplify the provisions of this Lease.


44.      ENTIRE AGREEMENT

         This Lease represents the entire agreement between Landlord and Tenant
         and supersedes all prior agreements both written and oral. The terms,
         covenants and conditions of this Lease shall be binding upon and shall
         inure to the benefit of Landlord and Tenant and their respective
         executors, administrators, heirs, distributes, legal representatives,
         successors and assigns. The term "Tenant" as used in this Lease shall
         include Xerox Corporation and any subsidiary (or any subsidiary of any
         subsidiary) of Xerox Corporation.


45.      CHOICE OF LAW AND INTERPRETATION

         This Lease shall be governed by the law of the State in which the
         Complex is situate. Should any provisions of this Lease require
         judicial interpretation, it is agreed that the court interpreting or
         construing the same shall not apply a presumption that the terms of any
         such provision shall be more strictly construed against one party or
         the other by reason of the rule of construction that a document is to
         be construed most strictly against the party who itself or through its
         agent prepared the same, it being agreed that the agents of all parties
         hereto have participated in the preparation of this Lease.


46.      ARBITRATION OF DISPUTES

         All disputes between Landlord and Tenant with respect to Paragraph 16
         of this Lease, with respect to the determination of fair market value
         rental rates, shall be decided by arbitration. Tenant shall have the
         right, by giving written notice to 
<PAGE>   70
         Landlord, setting forth in detail the nature of the dispute, to request
         arbitration. The dispute shall be submitted to arbitration as follows:

         Within fifteen (15) business days after delivery of the above notice,
         each party (Landlord and Tenant) shall appoint a person to act as an
         arbitrator in its behalf.


                                       16
<PAGE>   71
         Within five (5) business days thereafter the two appointed arbitrators
         shall jointly appoint a third arbitrator. The dispute shall be
         arbitrated by said three arbitrators. A majority decision of the three
         arbitrators shall control. All of the arbitrators shall be persons
         having at least ten (10) years experience in dealing with commercial
         leases in office buildings within the City of San Diego, State of
         California, and none shall have any interest in the Building or the
         Complex or be or have been associated or affiliated with either
         Landlord or Tenant.

         In the event Landlord and Tenant, or the two arbitrators fail or refuse
         to appoint an arbitrator within the time set forth herein, then either
         party shall have the right to petition the senior judge (in terms of
         years of service), of the United States District Court of the
         applicable Federal District in which the Building is situate, to
         appoint such arbitrator and the arbitrator appointed by said judge
         shall serve in said capacity.

         NOTICE: BY INITIALING IN THE SPACE BELOW YOU ARE AGREEING TO HAVE ANY
         DISPUTE ARISING OUT OF THE MATTERS INCLUDED IN THE ARBITRATION OF
         DISPUTES PROVISION DECIDED BY NEUTRAL ARBITRATION AS PROVIDED BY
         CALIFORNIA LAW, AND YOU ARE GIVING UP ANY RIGHTS YOU MIGHT POSSESS TO
         HAVE THE DISPUTE LITIGATED IN A COURT OR JURY TRIAL BY INITIALING IN
         THE SPACE BELOW, YOU ARE GIVING UP YOUR JUDICIAL RIGHTS TO DISCOVERY
         AND APPEAL UNLESS SUCH RIGHT ARE SPECIFICALLY INCLUDED IN THE
         "ARBITRATION OF DISPUTES" PROVISION. IF YOU REFUSE TO SUBMIT TO
         ARBITRATION AFTER AGREEING TO THIS PROVISION, YOU MAY BE COMPELLED TO
         ARBITRATE UNDER THE AUTHORITY OF THE CALIFORNIA CODE OF CIVIL
         PROCEDURE. YOUR AGREEMENT TO THIS ARBITRATION PROVISION IS VOLUNTARY.
         WE HAVE READ AND UNDERSTAND THE FOREGOING AND AGREE TO SUBMIT DISPUTES
         ARISING OUT OF THE MATTERS INCLUDED IN THE "ARBITRATION OF DISPUTES"
         PROVISION TO NEUTRAL ARBITRATION.


         /s/ MR                                 /s/ MF
         ----------------------------           -----------------------------
         Initialed by Landlord                  Initial by Tenant


47.      EXHIBITS AND RIDERS

         Attached hereto and made a part hereof are the following:

         EXHIBIT A:                 COMPLEX
         EXHIBIT B:                 DEMISED PREMISES
         EXHIBIT B-1:               PRELIMINARY SPACE PLAN
         EXHIBIT C:                 PLANS AND SPECIFICATIONS
         EXHIBIT D:                 LEASE TERM AGREEMENT
         EXHIBIT E:                 CLEANING SCHEDULE
         EXHIBIT F:                 NON-DISTURBANCE AND ATTORNMENT AGREEMENT
         EXHIBIT G:                 MEMORANDUM OF LEASE


                                       17
<PAGE>   72
IN WITNESS WHEREOF, Landlord and Tenant have duly executed this Lease as of the
day and year first above written.






WITNESS:                                GOVERNOR PARK ASSOCIATES
                                        a California Limited Partnership



                                        By:      /s/ Michael J. Reidy
                                                 ----------------------------
                                                 Michael J. Reidy
                                        Its:     Managing Partner

                                                                  (Landlord)



WITNESS:                                XEROX CORPORATION


-----------------------------------  
                                        By:/s/ Mark A. Flaim
                                           -----------------------------------
                                        Mark A. Flaim
                                        Manager, Real Estate Operations
                                        Western United States

                                                                  (Tenant)


                                       18