1 Exhibit 15 THE ASK GROUP, INC. 2880 SCOTT BOULEVARD P.O. BOX 58013 SANTA CLARA, CA 95052-8013 May 18, 1994 Electronic Data Systems Corporation 7171 Forest Lane Dallas, Texas 75230 Attn: President, Manufacturing and Distribution Division Ladies & Gentlemen: This letter is being delivered to you in connection with the transactions contemplated by the Stockholder Option Agreement, dated as of May 18, 1994, among Speedbird Merge, Inc. ("Merger Sub") and certain holders of the shares of Common Stock of The ASK Group, Inc. (the "Company"), including Electronic Data Systems Corporation ("EDS"). Reference is also made to that certain Agreement and Plan of Merger, dated as of May 18, 1994 (the "Merger Agreement"), among Computer Associates International, Inc. ("CA"), Merger Sub and the Company. As an inducement to CA and Merger Sub to enter into the Merger Agreement, you agree that, effective upon the execution and delivery of the Stockholder Option Agreement and the Merger Agreement and for as long as the Merger Agreement has not been terminated in accordance with its terms, all rights that you have under Section 7.8 of the Common Stock Purchase Agreement, dated as of August 31, 1990 (the "Purchase Agreement") among the Company, EDS and Hewlett-Packard Company, whether presently existing or arising as a result of the transactions contemplated by the Merger Agreement, are hereby waived and released. Very truly yours, The ASK Group, Inc. By: ________________________________ Title: _____________________________ AGREED as of May 18, 1994: ELECTRONIC DATA SYSTEMS CORPORATION By: _______________________________