EXHIBIT 99.3

                              IKOS SYSTEMS, INC.
                   Proxy for Special Meeting of Stockholders
                      Solicited by the Board of Directors

   The undersigned hereby appoints Ramon A. Nunez and Joseph W. Rockom, and
each of them, with full power of substitution to represent the undersigned and
to vote all of the shares of common stock of IKOS Systems, Inc. (the
"Company") which the undersigned is entitled to vote at the Special Meeting of
Stockholders of said Company to be held at [      ] on [     ,  , 2001 at
10:00 a.m. Pacific Standard Time], and at any adjournment or postponement
thereof (1) as hereinafter specified upon the proposals listed below and as
more particularly described in the Company's Proxy Statement, receipt of which
is hereby acknowledged and (2) in their discretion upon such other matters as
may properly come before the meeting.

   A vote FOR the following proposal is recommended by the Board of Directors:

     1. To adopt the agreement and plan of merger and reorganization, dated
  July 2, 2001, as amended, by and among Synopsys, Inc., Oak Merger
  Corporation, a wholly-owned subsidiary of Synopsys, and the Company
  pursuant to which, among other things, Oak Merger Corporation will merge
  with and into IKOS and IKOS will become a wholly-owned subsidiary of
  Synopsys and each outstanding share of IKOS common stock will be converted
  into the right to receive the number of shares (or fraction of a share) of
  Synopsys common stock prescribed by the agreement.

                    [_] FOR         [_] WITHHELD       [_] ABSTAIN

     2. To transact such other business as may properly come before the
  special meeting.

   The shares represented hereby shall be voted as specified. If no
specification is made, such shares shall be voted FOR proposal 1.

   THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS OF THE COMPANY

                                         Dated
                                               ________________________________
                                               (Be sure to date Proxy)

                                               ________________________________
                                               Signature(s)

                                               ________________________________
                                               Print Name(s)

Sign exactly as your name(s) appears on your stock certificate. If shares of
stock stand on record in the names of two or more persons or in the name of
husband and wife, whether as joint tenants or otherwise, both or all of such
persons should sign the above Proxy. If shares of stock are held of record by
a corporation, the Proxy should be executed by the President or Vice President
and the Secretary or Assistant Secretary, and the corporate seal should be
affixed thereto. Executors or administrators or other fiduciaries who execute
the above Proxy for a deceased stockholder should give their full title.
Please date the Proxy.

Even if you are planning to attend the meeting in person, you are urged to
sign and mail the Proxy in the return envelope so that your stock may be
represented at the meeting.