<PAGE>
                                                                  EXHIBIT 10.27

                              SEPARATION AGREEMENT
                           GENERAL RELEASE AND WAIVER

                  SEPARATION AGREEMENT and GENERAL RELEASE and WAIVER (this
"Agreement") made as of December 3, 2001 (the "Execution Date"), by and between
John Howard Hsu (the "Employee") and Avant! Corporation, (the "Employer,"
together with the Employee, the "Parties").

                  WHEREAS, the Employer engaged the Employee to be an employee
of the Employer;

                  WHEREAS, the Employee and the Employer are parties to an
Employment Agreement, dated October 1, 2000 (the "Employment Agreement"); and

                  WHEREAS, the Parties wish to confirm the termination of the
Employee's employment with the Employer and set forth their agreement as to the
manner in which the Employee's employment with the Employer will be closed out.

                  NOW, THEREFORE, in consideration of the mutual covenants set
forth herein and for other good and valuable consideration, receipt of which is
hereby acknowledged, the Parties agree as follows:

                  1. Confirmation of Termination. The Parties hereby now
acknowledge and confirm that the Employee's employment with the Employer and its
affiliates (as defined in Rule 12b-2 under the Securities Exchange Act of 1934,
as amended (the "Affiliates" and the "Exchange Act") shall terminate as of
December 3, 2001 (the "Termination Date"). The Employee hereby resigns,
effective as of the Termination Date, all positions, titles, duties, authorities
and responsibilities with, arising out of or relating to his employment with the
Employer or its Affiliates, including all positions on the board of directors
(or any committee thereof) of the Employer or its Affiliates. The Employment
Agreement is hereby terminated, except only for provisions thereof that are
expressly declared below to remain effective.

                  2.       Termination Payment.

                  (a) Not later than 10 days after the Termination Date, the
Employer shall pay the Employee the sum of (i) one million fifty thousand
dollars ($1,050,000), and (ii) any unpaid salary, expense reimbursement,
previously deferred compensation, vacation pay or other regular employee
benefits (but specifically excluding bonus amounts) to which the Employee may be
entitled up to the Termination Date.

                  (b) All options granted by the Company and presently held by
the Employee to purchase common stock of the Employer shall vest in full upon
the Termination Date and shall thereafter be exercisable at any time or times
until their respective expiration dates or, if earlier, upon the Effective Time
(as such term is defined in the "Agreement and Plan of Merger" dated on or about
the date of this Agreement among the Employer, Synopsys, Inc. and Maple Forest
Acquisition LLC (the "Synopsys Acquisition").


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<PAGE>
                  (c) The amount set forth in Section 2(a)(i) shall be referred
to herein as the "Termination Payment." The Termination Payment and other
amounts due under Section 2(a) shall be reduced by any required tax
withholdings. The Termination Payment shall not be taken into account as
compensation under, and no service credit shall be given for the Termination
Payment for purposes of determining the benefits payable under, any benefit
plan, program, agreement or arrangement of the Employer or its Affiliates. The
Employee acknowledges that, except for the Termination Payment and other amounts
payable to him under Section 2(a), the acceleration of his options under Section
2(b), and payments provided under Section 6 (entitled "Indemnification"), he is
not entitled to any payment in the nature of severance or termination pay from
the Employer or any of its Affiliates and is not entitled to any other amount,
payment or benefit, of any nature whatsoever, from the Employer or any of its
Affiliates, including, without limitation, under any employee benefit plan,
program or arrangement of the Employer or its Affiliates (other than any vested
benefit under the Employer's 401(k) plan) or under the Employment Agreement.

                  (d) The Employer acknowledges that its agreement to make the
Termination Payment and to accelerate the vesting of the Employee's options, as
described in Sections 2(a) and 2(b), respectively, reflects the Employee's
agreement herein to relinquish certain valuable rights under the Employment
Agreement and to undertake significant obligations not imposed on him under the
Employment Agreement. By way of examples only: (1) the Employee is agreeing in
Section 5 to a post-employment covenant not to compete that substantially
exceeds the scope and duration of the post-employment covenant not to compete to
which he agreed in Section 3 of the Employment Agreement; (2) the Employee is
relinquishing his right to receive $2,000,000 under Section 3(D) of the
Employment Agreement as compensation for his covenant not to compete described
in Section 3 of the Employment Agreement; (3) the Employee is releasing the
Employer from any claim based on Constructive Termination of his employment as
the result of a Change in Control (as those terms are defined in Section 2 of
the Employment Agreement - "Constructive Termination" and "Change in Control")
that occurred when Gerald C. Hsu ceased to be the Employer's CEO in July 2001;
and (4) the Employee is voluntarily terminating his employment presently even
though the Employee recognizes that the Synopsys Acquisition is expected to
close within the next several months and that such Acquisition, if closed, would
constitute a Change in Control that could give rise to a claim of Constructive
Termination by the Employee. The Employer acknowledges that it does not have
good cause, or any desire, to terminate the Employee's employment now or at any
time prior to the anticipated closing of the Synopsys Acquisition, that it has
been fully satisfied with the Employee's performance as an employee of the
Employer, and that it is not aware of any basis apart from this Agreement on
which it could in good faith terminate the Employee's employment now or at any
time prior to the anticipated closing of the Synopsys Acquisition. The Employer
further acknowledges its beliefs, based on communications with representatives
of Synopsys, that (i) Synopsys does not presently expect that it will desire to
retain the Employee as an employee after the closing of the Synopsys
Acquisition; and (ii) the making of this Agreement will increase the likelihood
that the Synopsys Acquisition will be consummated, which the Employer believes
will be beneficial to the Employer and its shareholders. This Agreement
nevertheless shall be effective immediately and shall not be terminated in the
event that the Synopsys Acquisition fails to close for any reason.


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                  3.       General Releases and Waivers

                  (a) General Release and Waiver by Employer ("RELEASE")

                      (i) Employer, on behalf of itself, its subsidiaries and
           Affiliates, its directors, managing directors, officers, control
           persons, stockholders, employees, agents, attorneys, administrators,
           successors and assigns (collectively, "RELEASOR"), for good and
           valuable consideration received from the Employee, releases and
           discharges the Employee and his heirs, executors, agents, attorneys,
           administrators, successors and assigns (collectively, "RELEASEE")
           from any claim or cause of action, accounts, agreements, bonds,
           bills, covenants, contracts, controversies, claims, damages, demands,
           debts, dues, extents, executions, judgments, liabilities,
           obligations, promises, predicate acts, reckonings, specialties,
           suits, sums of money, trespasses and variances, including without
           limitation court costs and attorneys fees, in law or in equity, which
           RELEASOR has as of the Execution Date against RELEASEE that are based
           on actions or omissions of RELEASEE occurring prior to the Execution
           Date which, as of the Execution Date (A) are known to RELEASOR, or
           (B) have been disclosed in a publicly available report or other
           document filed on or before the Execution Date with the U.S.
           Securities and Exchange Commission by or on behalf of RELEASEE or the
           Employer, or (C) have been disclosed to RELEASOR by RELEASEE or the
           Employer on or before the Execution Date, the information described
           in (A), (B) and (C) being hereinafter referred to as the "Disclosed
           Facts" (collectively, the "RELEASED MATTERS"). For the purposes of
           this paragraph, a claim against RELEASEE shall be deemed to have
           existed as of the Execution Date if such claim is based upon actions
           or omissions of RELEASEE that occurred or began prior to the
           Execution Date, even if (i) RELEASOR's right to damages or equitable
           relief on such claim had not matured as of the Execution Date; or (2)
           RELEASOR became entitled to additional or different legal or
           equitable relief on such claim after the Execution Date as a result
           of a continuation of the same actions or omissions or the effects
           thereof, and/or the passage of time, after the Execution Date, and
           such claim shall be deemed to include the right to any such
           additional or different relief. "RELEASED MATTERS" do not include any
           claim that RELEASOR may now or hereafter have against the Employee's
           father, Gerald Hsu, to the extent such a claim is based on actions or
           omissions of Gerald Hsu rather than actions or omissions of the
           Employee.

                      (ii) THE PARTIES ACKNOWLEDGE THAT THEY ARE FAMILIAR WITH
           SECTION 1542 OF THE CIVIL CODE OF THE STATE OF CALIFORNIA, WHICH
           PROVIDES AS FOLLOWS:

                      "A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE
           CREDITOR DOES NOT KNOW OR SUSPECT TO EXIST IN HIS FAVOR AT THE TIME
           OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM MUST HAVE MATERIALLY
           AFFECTED HIS SETTLEMENT WITH THE DEBTOR."

                      RELEASOR EXPRESSLY WAIVES AND RELINQUISHES ANY RIGHT OR
           BENEFIT WHICH IT HAS OR MAY HAVE UNDER SECTION 1542 OF THE CIVIL CODE
           OF THE STATE OF CALIFORNIA, OR ANY OTHER STATUTE OR


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           LEGAL PRINCIPLE WITH SIMILAR EFFECT WITH RESPECT TO CLAIMS BASED ON
           OR ARISING FROM THE DISCLOSED FACTS, BUT RELEASOR DOES NOT WAIVE OR
           RELINQUISH ANY SUCH RIGHT OR BENEFIT WITH RESPECT TO CLAIMS THAT ARE
           NOT BASED ON OR DO NOT ARISE FROM THE DISCLOSED FACTS.

                      RELEASEE acknowledges that he is aware that, after
           executing this RELEASE, RELEASOR or its attorneys or agents may
           discover facts in addition to or different from the Disclosed Facts,
           and that it is the intention of RELEASOR and RELEASEE not to settle
           and release any claim or cause of action, accounts, agreements,
           bonds, bills, covenants, contracts, controversies, claims, damages,
           demands, debts, dues, extents, executions, judgments, liabilities,
           obligations, promises, predicate acts, reckonings, specialties,
           suits, sums of money, trespasses and variances, including without
           limitation court costs and attorneys fees, in law or in equity, which
           may exist on the basis of facts other than the Disclosed Facts.

                      (iii) The RELEASED MATTERS do not include any claims for
           the breach by RELEASEE or any person or entity acting on his behalf
           of the obligations arising under this Agreement.

                      (iv) Nothing in this Release is intended to, or shall be
           construed or claimed to be, a license in favor of RELEASEE with
           respect to any property of RELEASOR, the Employer, or any other
           person or entity.

                      (v) This RELEASE may not be modified or amended except by
           an instrument in writing signed by the RELEASOR and the RELEASEE.

                  (b) General Release and Waiver by the Employee ("EMPLOYEE
RELEASE").

                      (i) The Employee on behalf of himself, his heirs,
           executors, agents, attorneys, administrators, successors and assigns
           (collectively, "EMPLOYEE RELEASOR"), for good and valuable
           consideration received from the Employer or its Affiliates, hereby
           releases and discharges the Employer, its subsidiaries and Affiliates
           and their respective present and former directors, managing
           directors, officers, control persons, stockholders, employees,
           agents, attorneys, administrators, successors and assigns
           (collectively, "EMPLOYER RELEASEE"), from any claim or cause of
           action, accounts, agreements, bonds, bills, covenants, contracts,
           controversies, claims, damages, demands, debts, dues, extents,
           executions, judgments, liabilities, obligations, promises, predicate
           acts, reckonings, specialties, suits, sums of money, trespasses and
           variances, including without limitation court costs and attorneys
           fees, in law or in equity, which EMPLOYEE RELEASOR has as of the
           Execution Date against EMPLOYER RELEASEE that are based on actions or
           omissions of EMPLOYER RELEASEE occurring prior to the Execution Date
           which, as of the Execution Date (A) are known to EMPLOYEE RELEASOR;
           or (B) have been disclosed in a publicly available report or other
           document filed on or before the Execution Date with the U.S.
           Securities and Exchange Commission by or on behalf of the Employer,
           or (C) have been disclosed to EMPLOYEE RELEASOR by EMPLOYER RELEASEE
           or the


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           Employer on or before the Execution Date, the information described
           in (A), (B) and (C) being hereinafter referred to as the "Facts
           Disclosed to EMPLOYEE RELEASOR" (collectively, the "EMPLOYEE RELEASED
           MATTERS"), including, without limitation, under the Americans with
           Disabilities Act of 1990, the Family and Medical Leave Act of 1993,
           Title VII of the United States Civil Rights Act of 1964, 42 U.S.C.
           Section 1981, the California Fair Employment and Housing Act,
           California's Unruh Civil Rights Act, Section 51 of the California
           Civil Code, the California Labor Code, the California Family Rights
           Act, or any other Federal, state, or local law and any workers'
           compensation or disability claims under any such laws. This EMPLOYEE
           RELEASE relates to claims arising from or during Employee's
           employment relationship with the Employer or its Affiliates or as a
           result of the termination of such relationship. The EMPLOYEE RELEASOR
           further agrees that the EMPLOYEE RELEASOR will not file or permit to
           be filed on EMPLOYEE RELEASOR'S behalf any such claim.
           Notwithstanding the preceding sentence or any other provision of this
           Agreement, this EMPLOYEE RELEASE is not intended to interfere with
           EMPLOYEE RELEASOR's right to file a charge with the Equal Employment
           Opportunity Commission in connection with any claim EMPLOYEE RELEASOR
           believes EMPLOYEE RELEASOR may have against EMPLOYER RELEASEE.
           However, by executing this Agreement, EMPLOYEE RELEASOR hereby waives
           the right to recover in any proceeding EMPLOYEE RELEASOR may bring
           before the Equal Employment Opportunity Commission or any state human
           rights commission or in any proceeding brought by the Equal
           Employment Opportunity Commission or any state human rights
           commission on EMPLOYEE RELEASOR'S behalf. This EMPLOYEE RELEASE is
           for any relief, no matter how denominated, including, but not limited
           to, injunctive relief, wages, back pay, front pay, compensatory
           damages, or punitive damages. This EMPLOYEE RELEASE shall not apply
           to any obligation of the Employer pursuant to this Agreement, nor to
           any right to indemnification that the Employee may now or hereafter
           have under Section 6, statute, or the Employer's certificate of
           incorporation or bylaws.

                      Without limiting the breadth of the preceding paragraph,
           "EMPLOYEE RELEASED MATTERS" shall include any claim, not based on
           Facts Disclosed to EMPLOYEE RELEASOR, that EMPLOYEE RELEASOR may now
           or hereafter have against EMPLOYER RELEASEE based on any transaction
           described in Item 404 of Regulation S-K under the Exchange Act
           involving or relating to the Employer or any of its "subsidiaries"
           (as such term is defined in Rule 12b-2 under the Exchange Act) (i) to
           which the Employee or any member of his "immediate family" (as such
           term is defined in Rule 16a-1 under the Exchange Act) is presently a
           party, or (ii) in which the Employee presently has any "pecuniary
           interest" (as such term is defined in the next sentence). For
           purposes of this paragraph, the term "pecuniary interest" means the
           opportunity, directly or indirectly, to profit or share in any profit
           derived from a transaction, including any "indirect pecuniary
           interest" (as such term is defined in Rule 16a-1 under the Exchange
           Act) and, for purposes of clarification, determined without regard to
           whether the transaction involves any securities of the Employer or
           any subsidiary. The Employee shall be liable to the Employer for any
           damages resulting to the Employer from a transaction to which the
           first sentence of this paragraph applies,


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         but only to the extent of the Employee's pecuniary interest in such
         transaction and only if the facts concerning such transaction are not
         Disclosed Facts.

                      "EMPLOYEE RELEASED MATTERS" does not include any claim
           that any heir of the Employee may now or hereafter have against
           EMPLOYER RELEASEE, except for any such claim that is based solely on
           the status of such person as an heir of the Employee.

                      (ii) THE PARTIES ACKNOWLEDGE THAT THEY ARE FAMILIAR WITH
           SECTION 1542 OF THE CIVIL CODE OF THE STATE OF CALIFORNIA, WHICH
           PROVIDES AS FOLLOWS:

                      "A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE
           CREDITOR DOES NOT KNOW OR SUSPECT TO EXIST IN HIS FAVOR AT THE TIME
           OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM MUST HAVE MATERIALLY
           AFFECTED HIS SETTLEMENT WITH THE DEBTOR."

                      EMPLOYEE RELEASOR, HAVING READ AND UNDERSTOOD SECTION 1542
           AND BEEN ADVISED BY HIS OWN COUNSEL CONCERNING SECTION 1542 AND THE
           LEGAL EFFECT OF A WAIVER THEREOF, EXPRESSLY WAIVES AND RELINQUISHES
           ANY RIGHT OR BENEFIT WHICH HE HAS OR MAY HAVE UNDER SECTION 1542 OF
           THE CIVIL CODE OF THE STATE OF CALIFORNIA, OR ANY OTHER STATUTE OR
           LEGAL PRINCIPLE WITH SIMILAR EFFECT WITH RESPECT TO CLAIMS BASED ON
           OR ARISING FROM FACTS DISCLOSED TO EMPLOYEE RELEASOR, BUT EMPLOYEE
           RELEASOR DOES NOT WAIVE OR RELINQUISH ANY SUCH RIGHT OR BENEFIT WITH
           RESPECT TO CLAIMS THAT ARE NOT BASED ON OR DO NOT ARISE FROM FACTS
           DISCLOSED TO EMPLOYEE RELEASOR.

                      EMPLOYER RELEASEE acknowledges that it is aware that,
           after executing this EMPLOYEE RELEASE, EMPLOYEE RELEASOR or his
           attorneys or agents may discover facts in addition to or different
           from the Facts Disclosed to EMPLOYEE RELEASOR, and that it is the
           intention of EMPLOYEE RELEASOR and EMPLOYER RELEASEE not to settle
           and release any claim or cause of action, accounts, agreements,
           bonds, bills, covenants, contracts, controversies, claims, damages,
           demands, debts, dues, extents, executions, judgments, liabilities,
           obligations, promises, predicate acts, reckonings, specialties,
           suits, sums of money, trespasses and variances, including without
           limitation court costs and attorneys fees, in law or in equity, which
           may exist on the basis of facts other than the Facts Disclosed to
           EMPLOYEE RELEASOR.

                      (iii) This EMPLOYEE RELEASE may not be modified or amended
           except by an instrument in writing signed by the EMPLOYEE RELEASOR
           and the EMPLOYER RELEASEE.


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                      (iv) The EMPLOYEE RELEASED MATTERS do not include any
           claims for the breach by any person other than the Employee of
           obligations arising under this Agreement.

                  4.       Confidential Information.

                  (a) The Employee agrees and acknowledges that the Proprietary
Information and Inventions Agreement executed by him continues in full force and
effect in accordance with its terms, except to the extent that Section 4(b) or
Section 5 of this Agreement expressly state a more limited scope or duration of
the Employee's obligations not to disclose the Employer's confidential
information or to compete with the Employer or the Synopsys Group.

                  (b) The Employee recognizes that as an Employee of the Company
he has had access to secret and confidential information regarding the Company,
its products, customers and plans relating to the electronic design automation
industry. The Employee acknowledges that such information is of great value to
the Company, and is the sole property of the Company and that such information
has been acquired by him in confidence. In consideration of the obligations
undertaken by the Company as set forth herein, the Employee will not, at any
time, for a period of one year after the Termination Date, reveal, divulge or
make known, except as authorized by the Company or required on its behalf or
required pursuant to legal or administrative processes, any information of a
confidential nature concerning the Company's business involving the EDA industry
acquired by the Employee during the course of his employment to any competitor
to the Company in the EDA industry. Notwithstanding the preceding sentence, the
Employee's obligation not to disclose trade secrets shall instead continue until
the fourth anniversary of the Termination Date with respect to trade secrets
related to the Employer's technology or financial information, or to the pricing
or other material terms or conditions of agreements between the Employer and any
of its customers.

                  5.       Covenant Not to Compete.

                  (a) The parties confirm that it is reasonably necessary for
the protection of the Employer that the Employee agree, and accordingly, the
Employee does hereby agree that he will not, directly or indirectly, except for
the benefit of the Employer, at any time during his employment hereunder and
thereafter for a period of four years from the date of termination of this
Agreement, provided the Employer shall duly perform its obligations to the
Employee pursuant to this Agreement:

           (i)    Become an officer, director, partner, associate, employee,
                  owner, agent, creditor, independent contractor, co-venturer or
                  otherwise, or be interested in or associated with any other
                  corporation, firm or business engaged, in any geographical
                  area in which the Employer (or, after the Synopsys Acquisition
                  closes, if ever, Synopsys, Inc.) and their respective
                  subsidiaries and Affiliates (the "Synopsys Group") is then
                  engaged, in making or selling one or more products competitive
                  with a product or products then being made or sold by the
                  Employer or the Synopsys Group in the EDA industry, which
                  products made or sold by the Employer or the Synopsys Group
                  accounted for at least 1% of the annual sales of either the
                  Employer or Synopsys, Inc. (including in each case their
                  respective subsidiaries


                                      -7-
<PAGE>
                  and affiliates) during the four fiscal quarter period ending
                  with the last fiscal quarter completed prior to the
                  Termination Date;

           (ii)   Solicit, cause or authorize, directly or indirectly, to be
                  solicited for or on behalf of himself or third parties, from
                  parties who were customers of the Employer in the EDA industry
                  at any time within one year prior to the cessation of his
                  employment hereunder, any business competitive to the business
                  transacted by the Employer with such customers in the EDA
                  industry;

           (iii)  Accept or cause or authorize, directly or indirectly, to be
                  accepted for or on behalf of himself or third parties, any
                  such business in the EDA industry from any such customers of
                  the Employer as defined in the preceding subsection;

           (iv)   Solicit, or cause or authorize, directly or indirectly, to be
                  solicited for employment for or on behalf of himself or third
                  parties, any persons who served in a full-time employee
                  capacity at any time within six months prior to the cessation
                  of his employment hereunder, the parties agree that the
                  restrictions set forth in this subsection shall not apply to
                  any solicitation directed by the Employee at the public in
                  general in publications available to the public in general or
                  any contact which Employee can demonstrate was initiated by
                  such employee, nor to any solicitation of Yvonne Liu (after
                  the merger agreement governing the Synopsys Acquisition has
                  been terminated as provided therein, or at least six months
                  after the Synopsys Acquisition has closed), Kevin Liu, David
                  Huang, D.J. Ma, Maggie Chen, C.S. Kuo or any relative of the
                  Employee.

           (v)    Take any public position contrary to a public position taken
                  by the Board of Directors of Employer, provided that the
                  foregoing shall not apply to actions taken by the Employee to
                  enforce his rights under this Agreement or to testimony or the
                  production of documents by the Employee which may be required
                  by legal process.

                  (b) The Employee agrees that any breach or threatened breach
by him of any provisions of this Section 5 shall entitle the Employer, in
addition to any other legal or equitable remedies available to it, to apply to
any court of competent jurisdiction to enjoin such breach or threatened breach.

                  (c) This Section 5 shall not be construed to prevent the
Employee from owning in the aggregate an amount not exceeding three per cent
(3%) of the issued and outstanding voting securities of any class of any
corporation which is in competition with the Employer in the EDA industry whose
voting capital stock is traded on a national securities exchange or in the
over-the-counter market. For this purpose "outstanding voting securities" shall
be deemed to include the voting securities issuable upon conversion of a
corporation's outstanding convertible securities, whether or not immediately
convertible, and the voting securities of a corporation issuable upon exercise
of outstanding warrants and options to acquire voting securities, whether or not
immediately exercisable, and "voting securities" of a corporation shall be
deemed to include securities convertible into or exercisable for voting capital
stock, valued at the number of shares such securities are convertible into or
exercisable for the purpose of determining percentage ownership of outstanding
voting securities.


                                      -8-
<PAGE>
                   (d)     [Intentionally omitted.]

                   (e)     [Intentionally omitted.]

                   (f) Notwithstanding anything in this Agreement to the
contrary, if the Employee violates any of the provisions of paragraph (a) hereof
during the four year period beginning on the Termination Date and fails to cease
such violation and to remedy the consequences of such violation within ninety
days after notice from the Employer or the Synopsys Group specifying such
violation and if the Employer or the Synopsys Group obtains a final judgment
from a court of competent jurisdiction to the effect that the Employee has
violated a provision of paragraph (a) and has failed to cease such violation and
to remedy the consequences of such violation within ninety days after notice
from the Employer or the Synopsys Group, the Employee agrees that he will
reimburse the Employer, immediately, for the amount of the Termination Payment.
The preceding sentence states the Employer's exclusive monetary remedy for such
a breach. In no event shall the Employee's aggregate liability for any breach or
breaches of any obligations under this Agreement exceed the amount of the
Termination Payment received by him.

                   (g) For the purpose of this Section 5, a company, entity or
person shall be deemed in competition with the Employer or the Synopsys Group if
such company, entity or person engages in the EDA industry or, to the knowledge
of the Employee, has definitive plans to engage in the EDA industry.

                   (h) Employee represents and warrants that, as of the
Termination Date, to the best of his knowledge after exercising reasonable care,
he is not in possession of any non-public Employer documents or other material
tangible or intangible Employer property, including non-public information
stored in computers or on computer disks, and non-public recorded or graphic
matter, obtained during his employment with Employer ("Employer Information").
Employee covenants that to the extent that, at any time following the
Termination Date, he discovers Employer Information that was inadvertently
retained by him, he will promptly destroy such Employer Information.

                   (i) The restrictions imposed on the Employee's activities
under this Section 5 shall not be interpreted to restrict any activities of the
Employee that are not materially related to the EDA industry, nor to the
Employee's donation of any money, property or services to any educational,
scientific or religious organization as defined in Section 501(c)(3) of the
Internal Revenue Code, as amended (or any such organization that would fall
within such definition if the entire world were part of the United States).

                   (j) The Employee hereby agrees that it is impossible to
measure in money the damages which will accrue to the Employer or the Synopsys
Group by reason of a failure by the Employee to perform any of his obligations
under this Section 5. Accordingly, notwithstanding Section 7 of this Agreement,
if the Employer or the Synopsys Group institutes any action or proceeding to
enforce the provisions hereof, to the extent permitted by applicable law, the
Employee hereby waives the claim or defense that the Employer or the Synopsys
Group has an adequate remedy at law, and the Employee shall not urge in any such
action or proceeding the claim or defense that any such remedy at law exists.


                                      -9-
<PAGE>
                  6.       Indemnification.

                  Section 5 of the Employment Agreement is set forth below for
convenient reference:

         To the fullest extent not inconsistent with applicable law, in the
         event that the Employee is a party or is threatened to be made a party
         to any threatened, pending or completed action, suit or proceeding,
         whether civil, criminal, administrative or investigative, by reason of
         the fact that he is or was a director, officer, consultant, employee or
         agent of the Company or any of its subsidiaries, or is or was serving
         at the request of the Company as a director, officer, consultant,
         employee or agent of another Company, partnership, joint venture, trust
         or other enterprise, the Company shall indemnify the Employee and hold
         him harmless, against all expenses (including costs and attorneys'
         fees), judgments, fines and amounts paid in settlement actually and
         reasonably incurred by his in connection with such action, suit or
         proceeding if he acted in good faith and in a manner he reasonably
         believed to be in or not opposed to the best interests of the Company,
         and, with respect to any criminal action or proceeding, had no
         reasonable cause to believe his conduct was unlawful. The termination
         of any action, suit or proceeding by judgment, order, settlement,
         conviction, or upon a plea of nolo contendere or its equivalent, shall
         not, of itself, create a presumption that the Employee did not act in
         good faith and in a manner which he reasonably believed to be in or not
         opposed to the best interest of the Company, or that, with respect to
         any criminal action or proceeding, the Employee had reasonable cause to
         believe that his conduct was unlawful. The provisions of this Section 5
         shall not be deemed exclusive of any other rights of indemnification to
         which the Employee maybe entitled or which may be granted to him, and
         it shall be in addition to any rights of indemnification to which he
         may be entitled under any policy of insurance. The provisions of this
         Section 5 shall continue in effect after the Employee has ceased to be
         an officer, employee or agent of the Company, shall inure to the
         benefit of the Employee's heirs, executors, administrators and in
         testate distributes [sic] and shall survive the termination of this
         Agreement under all circumstances.

         All litigation or inquiries by third parties (for example, but not
         limited to, those by shareholders - direct or derivative - or
         government agencies) arising out of or in connection with this
         Agreement or the Employee's performance hereunder, against either the
         Company or the Employee or both, shall be defended or opposed by the
         parties hereto, as the case may be, to support this Agreement, and the
         costs, fees and expenses thereof, including fees of counsel for the
         parties, shall be borne by the Company.

         Notwithstanding the foregoing provisions of this Section 5, during the
         term of the Employee's employment hereunder and during such time he
         continues as an officer, the Company agrees to maintain substantially
         the same Officers' liability insurance in place on the date hereof and
         shall increase such coverage in the event the Employee determines that
         it is in the best interest of the Company to have such increased
         coverage.


                                      -10-
<PAGE>
                  Section 5 of the Employment Agreement, as set forth above,
shall remain fully effective after the Termination Date, and the Employee shall
further be entitled to indemnification as may be provided by statute or the
Employer's certificate of incorporation or bylaws. The Employee shall not
unreasonably withhold his consent to the settlement of any litigation or other
proceeding as to which the Employee is indemnified under this Section 6 or any
other indemnification provision, provided that such settlement will not require
payment of any material amount by the Employee or otherwise result in a material
detriment to the Employee.

                  7.       Arbitration

                  Except for any controversy or claim between the Company and
Employee to which Section 5(i) applies, any controversy or claim between the
Employer and Employee, their representatives, heirs, successors and assigns,
arising out of or relating to this Agreement or any breach or asserted breach
hereof or questioning the validity and binding effect hereof shall be determined
by arbitration conducted in San Francisco in accordance with the Rules of the
American Arbitration Association then obtaining, and judgment upon any award
rendered may be entered in any court having jurisdiction thereof. The decision
of the arbitrators shall be final and binding upon the parties hereto. All of
the Employee's costs and expenses (including attorneys, fees) arising out of or
in connection with any matters submitted to arbitration pursuant to this
subsection shall be paid by the Employer, unless the award of the arbitrators
shall explicitly find that the Employee's claim or his defense against a claim
by the Employer was frivolous and completely without merit, in which case the
Employee shall pay the costs and expenses (including, without limitation,
reasonable attorneys, fees) incurred by the Employer in such connection.

                  8.       No Admission

                  This Agreement does not constitute an admission of liability
or wrongdoing of any kind by the Employer or its Affiliates.

                  9.       Heirs and Assigns

                  The terms of this Agreement shall be binding on the Parties
hereto and their respective successors and assigns.

                  10.      General Provisions

                  (a)      Notice

                  Any notice or other communication required or permitted under
this Agreement shall be effective only if it is in writing and shall be deemed
to be given when delivered personally or four days after it is mailed by
registered or certified mail, postage prepaid, return receipt requested or one
day after it is sent by a reputable overnight courier service and, in each case,
addressed as follows (or if it is sent through any other method agreed upon by
the Parties):


                                      -11-
<PAGE>
                  If to the Employee:

                  John H. Hsu
                  5295 Blackhawk Drive
                  Danville, California 94506

                  With a copy to:

                  Eric A. Brill, Esq.
                  3535 Clay Street
                  San Francisco, CA 94118

                  If to the Employer:

                  At its then-current United States headquarters office.

                  Or to such other address as any party hereto may designate by
notice to the other.

                  (b)      Integration

                  This Agreement constitutes the entire understanding of the
Employer and the Employee with respect to the subject matter hereof and
supersedes all prior understandings, written or oral, including the Employment
Agreement (except for those sections of the Employment Agreement that remain in
effect as expressly provided herein). The terms of this Agreement may be
changed, modified or discharged only by an instrument in writing signed by the
Parties hereto. A failure of the Employer or the Employee to insist on strict
compliance with any provision of this Agreement shall not be deemed a waiver of
such provision or any other provision hereof. In the event that any provision of
this Agreement is determined to be so broad as to be unenforceable, such
provision shall be interpreted to be only so broad as is enforceable.

                  (c)      Choice of Law

                  THIS AGREEMENT SHALL BE CONSTRUED, ENFORCED AND INTERPRETED IN
ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF DELAWARE, WITHOUT
REFERENCE TO PRINCIPLES OF CONFLICT OF LAWS.

                  (d)      Construction of Agreement

                  The Parties hereto acknowledge and agree that each Party has
reviewed and negotiated the terms and provisions of this Agreement and has had
the opportunity to contribute to its revision. Accordingly, the rule of
construction to the effect that ambiguities are resolved against the drafting
party shall not be employed in the interpretation of this Agreement. Rather, the
terms of this Agreement shall be construed fairly as to both Parties hereto and
not in favor or against either Party.


                                      -12-
<PAGE>
                  (e)      Counterparts

                  This Agreement may be executed in any number of counterparts
and by different Parties on separate counterparts, each of which counterpart,
when so executed and delivered, shall be deemed to be an original and all of
which counterparts, taken together, shall constitute but one and the same
Agreement.

                  10.      Acknowledgement

                  The Employee acknowledges that, by the Employee's free and
voluntary act of signing below, the Employee has had an opportunity to consult
with attorneys and other advisers of his choosing regarding this Agreement, has
reviewed all of the terms of this Agreement and fully understands all of its
provisions, including, without limitation, the general release and waiver set
forth therein, and agrees to all of the terms of this Agreement and intends to
be legally bound thereby.

                                        Avant! Corporation

                                        /s/  Clayton Parker
                                        -------------------------------
                                        Name:  Clayton Parker
                                        Title: General Counsel

                                        /s/ John Howard Hsu
                                        -------------------------------
                                        John Howard Hsu


                                      -13-