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                                                                     EXHIBIT 4.2

                                     FORM OF

                             SUBSCRIPTION AGREEMENT

         HADRON, INC., a New York corporation (the "Company"), hereby issues and
sells to _________________ ("Investor"), and Investor hereby purchases and pays
for, ___________________ (_____) units (the "Units"), each consisting of one
share of the restricted Common Stock, par value $0.02 per share, of the Company
(the "Shares") and one warrant to purchase one share of restricted Common Stock
of the Company for $0.75 per share for five (5) years from the date of this
agreement. The purchase price for each Unit is $0.75. Payment of the purchase
price for the Shares has been made by the Investor by delivery to the Company in
conjunction with the execution of this Agreement by wire transfer or otherwise
as the Company and the Investor have agreed, of __________________ ($_________).

         Investor represents and warrants that:

         (a) the Investor understands that the Shares have not been registered
under the Securities Act of 1933, as amended (the "Securities Act"), or any
state securities laws;

         (b) the Investor is acquiring the Shares for the Investor's own
account, not as a nominee or agent, and without a view to resale or other
distribution within the meaning of the Securities Act and the rules and
regulations thereunder, and that the Investor will not distribute any of the
Shares in violation of the Securities Act;

         (c) the Investor (i) acknowledges that the Shares must be held
indefinitely by the Investor unless subsequently registered under the Securities
Act or an exemption from registration is available, (ii) is aware that any
routine sales of Shares made pursuant to Rule 144 under the Securities Act, when
such Rule becomes available, may be made only in limited amounts and in
accordance with the terms and conditions of that Rule and that in such cases
where the Rule is not applicable, compliance with some other registration
exemption will be required, and (iii) is aware that Rule 144 is not currently
available for use by the Investor for resale of any of the Shares;

         (d) the Investor is an "accredited investor" as defined within Rule 501
promulgated under the Securities Act by virtue of the Investor being one or more
of the following (check all that apply):

         ___      a corporation or partnership with total assets in excess of
                  $5,000,000 which was not formed for the specific purpose of
                  acquiring the Shares

         ___      a natural person whose individual net worth, or joint net
                  worth with the Investor's spouse, on the date hereof, exceeds
                  $1,000,000

         ___      a natural person who had an individual income in excess of
                  $200,000 in each of the two most recent years or joint income
                  with the Investor's spouse in excess of $300,000 in each of
                  those years and has a reasonable expectation of reaching the
                  same level of income in the current year

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         ___      a member of the Board of Directors or an officer of the
                  Company

         ___      an entity in which all of the equity owners are accredited
                  investors

         (e) the Investor has such knowledge and experience in financial and
business matters such that the Investor is capable of evaluating the merits and
risks of the Investor's investment in the Shares;

         (f) the Investor confirms that the Company has made available to the
Investor the opportunity to ask questions of and receive answers from the
Company concerning the terms and conditions of the Investor's investment in the
Shares, and the Investor has received to such Investor's satisfaction such
additional information about the Company's operations and prospects as such
Investor has requested;

         (g) the Investor agrees that the Investor will not sell or otherwise
transfer or dispose of Shares or any interest therein unless such Shares have
been registered under the Securities Act or may be sold or transferred in
reliance on an exemption from such registration; and

         (h) the Investor agrees that the certificates or instruments
representing the Shares and Warrants to be acquired by the Investor may contain
a restrictive legend noting the restrictions on transfer described herein and
required by federal and applicable state securities laws, and that appropriate
"stop-transfer" instructions may be given to the Company's transfer agent, if
any, provided that this paragraph (h) shall no longer be applicable to any
Shares following their transfer pursuant to a registration statement effective
under the Securities Act or in compliance with Rule 144 or if an opinion of
counsel reasonably satisfactory to the Company is to the effect that transfer
restrictions and the legend referred to herein are no longer required in order
to establish compliance with any provisions of the Securities Act.

HADRON, INC.                                INVESTOR

By:  ______________________________         ____________________________________
Name:  Jon M. Stout                         Printed Name:  _____________________
Title: President & CEO                      S.S. or T.I.N.  ____________________

Dated: August 11, 2000

                                       2<PAGE>

                                                          EXHIBIT 10 (a)

INDEPENDENT AUDITORS' CONSENT

We consent to the incorporation by reference in this Post-Effective Amendment
No. 17 to the Registration Statement on Form N-4 of Sun Life of Canada (U.S.)
Variable Account F (Reg. No. 33-41628) of our report dated February 10, 2000
accompanying the financial statements of Regatta, Regatta Gold, Regatta Classic
and Regatta Platinum Sub-Accounts included in Sun Life of Canada (U.S.)
Variable Account F, to the incorporation by reference of our report dated
February 10, 2000 accompanying the financial statements of Futurity, Futurity
II, Futurity Focus and Futurity Accolade Sub-Accounts included in Sun Life of
Canada (U.S.) Variable Account F appearing in the Statements of Additional
Information, which are part of such Registration Statement, to the
incorporation by reference of our report dated February 10, 2000 accompanying
the financial statements of Sun Life Assurance Company of Canada (U.S.), which
includes explanatory paragraphs relating to the use of statutory accounting
practices which differ from accounting principles generally accepted in the
United States of America, appearing in each of the Prospectuses, which are part
of such Registration Statement, and to the incorporation by reference of our
report dated February 10, 2000 appearing in the Annual Report on Form 10-K of
Sun Life Assurance Company of Canada (U.S.) for the year ended December 31,
1999, which includes explanatory paragraphs relating to the use of statutory
accounting practices which differ from accounting principles generally accepted
in the United States of America.

We also consent to the references to us under the headings "Accountants" and
Appendix B - "Condensed Financial Information - Accumulation Units Values"
in each Prospectus and under the heading "Accountants" in the Statement of
Additional Information relating to each Prospectus, which are incorporated by
reference in this Post-Effective Amendment No. 17.

DELOITTE & TOUCHE LLP

Boston, Massachusetts
September 8, 2000<PAGE>

                                                                   Exhibit 10(b)

                           REPRESENTATION OF COUNSEL

I, Sandra M. DaDalt, in my capacity as counsel to Sun Life of Canada (U.S.)
Variable Account F (the "Account") have reviewed this Post-Effective Amendment
No. 17 to the Registration Statement (File No. 33-41628) of the Account (the
"Post-Effective Amendment") which is being filed pursuant to paragraph (b) of
Rule 485 under the Securities Act of 1933. Based on my review of the
Post-Effective Amendment and such other material relating to the operations of
the Account as I deemed relevant, I hereby certify as of the date of filing the
Post-Effective Amendment, that the Post-Effective Amendment does not contain
disclosure which would render it ineligible to become effective pursuant to
paragraph (b) of Rule 485.

I hereby consent to the filing of this representation as part of the
Post-Effective Amendment.

                                              /s/ SANDRA M. DADALT
                                              ----------------------
                                              Sandra M. DaDalt, Esq.

August 31, 2000<PAGE>

INDEPENDENT AUDITORS' CONSENT

We consent to the incorporation by reference in this Post-Effective Amendment
No. 8 to the Registration Statement on Form N-4 of Sun Life of Canada (U.S.)
Variable Account F (Reg. No. 333-05227) of our report dated February 10, 2000
accompanying the financial statements of the Futurity, Futurity II, Futurity
Focus and Futurity Accolade Sub-Accounts included in Sun Life of Canada (U.S.)
Variable Account F, to the incorporation by reference of our report dated
February 10, 2000 accompanying the financial statements of the Regatta, Regatta
Gold, Regatta Classic and Regatta Platinum Sub-Accounts included in Sun Life of
Canada (U.S.) Variable Account F, appearing in the Statement of Additional
Information, which is part of such Registration Statement, to the incorporation
by reference of our report dated February 10, 2000 accompanying the financial
statements of Sun Life Assurance Company of Canada (U.S.), which includes
explanatory paragraphs relating to the use of statutory accounting practices
which differ from accounting principles generally accepted in the United States
of America, appearing in the MFS Regatta Classic Prospectus and the Futurity
Focus Prospectus, which are part of such Registration Statement, and to the
incorporation by reference of our report dated February 10, 2000 appearing in
the Annual Report on Form 10-K of Sun Life Assurance Company of Canada (U.S.)
for the year ended December 31, 1999, which includes explanatory paragraphs
relating to the use of statutory accounting practices which differ from
accounting principles generally accepted in the United States of America.

We also consent to the reference to us under the headings "Accountants" and
"Appendix B - Condensed Financial Information -- Accumulation Unit Values"
appearing in each Prospectus and under the heading "Financial Statements" in
the Statement of Additional Information relating to each Prospectus, which
are incorporated by reference in this Post-Effective Amendment No. 8.

DELOITTE & TOUCHE LLP
Boston, Massachusetts
September 8, 2000

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