FILED BY AVANT! CORPORATION PURSUANT TO RULE 425 UNDER THE SECURITIES ACT OF
1933. IN ADDITION, AVANT! CORPORATION DEEMS THIS COMMUNICATION TO BE FILED UNDER
RULE 14a-12 OF THE SECURITIES EXCHANGE ACT OF 1934. SUBJECT CORPORATION: AVANT!
CORPORATION, COMMISSION FILE NO. 0-25864.

ADDITIONAL INFORMATION

           In connection with the proposed merger, Synopsys and Avant! will file
a joint proxy statement/prospectus with the SEC. INVESTORS AND SECURITY HOLDERS
ARE URGED TO READ THE JOINT PROXY STATEMENT / PROSPECTUS REGARDING THE PROPOSED
MERGER WHEN IT BECOMES AVAILABLE, BECAUSE IT WILL CONTAIN IMPORTANT INFORMATION.
Investors and security holders may obtain a free copy of the joint proxy
statement / prospectus (when available) and other related documents filed by
Synopsys and Avant! with the SEC at the SEC's website at www.sec.gov. The joint
proxy statement / prospectus (when it is available) and the other documents may
also be obtained for free by accessing Synopsys' website at www.synopsys.com or
by directing a request by mail or telephone to 700 E. Middlefield Road, Mountain
View, CA 94043, Attention: Company Secretary, (650) 584-5000, or by accessing
Avant!'s website at www.avanticorp.com or by directing a request by mail or
telephone to 4671 Bayside Parkway, Fremont, CA 94538, Attention: Company
Secretary, (510) 413-8000.

           Synopsys, Avant!, and their respective directors, executive officers
and certain other members of management and employees may be soliciting proxies
from their respective stockholders in favor of the merger. Information regarding
the persons who may, under the rules of the SEC, be considered participants in
the solicitation of the Synopsys stockholders, or the Avant! stockholders, as
the case may be, in connection with the proposed merger, will be set forth in
the joint proxy statement / prospectus when it is filed with the SEC.

---------------------

On December 3, 2001, Avant! Corporation and Synopsis, Inc. announced that they
have entered into a merger agreement whereby Synopsys is to acquire Avant!.
Avant! filed the merger agreement under cover of Form 8-K today and the merger
agreement is incorporated by reference into this filing.



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