Exhibit 10.42

December 5, 1997

Joseph B.  Costello
914 Lundy Lane
Los Altos, CA 94024

Dear Joe:

On October 19, 1997 you resigned as Cadence's President and Chief Executive 
Officer and as member of its Board of Directors, and all other positions you 
may hold with Cadence.  As we discussed, Cadence is prepared to enter into 
the following agreement with you to facilitate a smooth transition for you 
and the Company.

Under our agreement, you became a part-time employee of Cadence from November 
1, 1997 and will continue in that capacity through July 15, 1998 (the 
"Part-Time Employment Period").  In this capacity, you will report to the 
President and Chief Executive Officer and provide such advice and assistance 
as is reasonably requested of you by him or other members of the Executive 
Staff for up to twenty (20) hours per month.  You will be free to engage in 
other employment during this period and Cadence will not require you to 
render part-time services to Cadence at a time or in a manner which would 
interfere with your ability to engage in such other employment.  Your salary 
for the Part-Time Employment Period will be $2,500 per month, subject to 
standard withholdings and deductions paid on our regular payroll schedule.

During your Part-Time Employment Period, you will not accrue vacation or 
receive Company benefits.  At the end of the Part-Time Employment Period, 
your employment with Cadence (and any subsidiary thereof) will terminate.  
During your Part-Time Employment Period, your Cadence stock options 
(including the option granted on April 11, 1996) will continue to vest 
according to their terms until the termination of your part-time employment.  
After the termination of your part-time employment, you will be able to 
exercise any of your vested options pursuant to the terms of each applicable 
option agreement.

The Employment Invention and Confidential Information Agreement 
("Confidentiality Agreement") which you signed on September 17, 1984, will 
continue to be in effect through your Part-Time Employment Period, and you 
will agree to comply with Cadence's employee policies and procedures.  In the 
event that Cadence terminates your part-time employment for cause, Cadence's 
obligation to pay your salary shall end and your stock vesting shall cease.(1)



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(1) Under this letter agreement, "cause" shall mean: (a) any gross misconduct 
or fraud in the performance of your employment; (b) a conviction or guilty 
plea with respect to any felony; (c) material breach of this agreement, your 
Confidentiality Agreement, or Cadence policies, after providing written 
notice to you of such breach and a reasonable opportunity to cure such 
breach, unless such breach cannot reasonably be cured; or (d) conduct by you 
which in the good faith and reasonable determination of the Board 
demonstrates gross unfitness to serve (e.g., sustained physical or mental 
disability).

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In order to protect the trade secrets and confidential and proprietary 
information of the Company, you agree that through May 31, 1999, you will not 
perform work for any business entity, or engage in any work activity which is 
in competition, or is preparing to compete, with the Company in its business 
of developing, marketing and providing services relating to electronic design 
automation software tools, or its services and consulting business involving 
electronic product design realization, design process optimization, and 
advice and implementation relating to electronics services and corporate and 
government development projects ("Competitive Activity").  If you are in 
doubt as to whether a particular work activity may comprise Competitive 
Activity, you will obtain the written consent of the Company's Board of 
Directors, which shall not be unreasonably withheld, before undertaking such 
work activity.  For purposes of this paragraph, the holding of less than five 
percent (5%) of the outstanding voting securities of any firm or business 
organization in competition with the Company shall not constitute activities 
or services precluded by this paragraph.

You also agree that through May 31, 1999, you will not directly or indirectly 
solicit or encourage any employee, independent contractor, supplier or 
customer of the Company to terminate his, her or its relationship with the 
Company.  Cadence agrees that general advertisements for employment not 
targeted, directly or indirectly, at Cadence shall not be prohibited under 
this paragraph.  Cadence also agrees that your Executive Administrator at 
Cadence, Peggy Thompson, may work for you as you engage in other employment 
activities.

You and the Company agree not to disparage the other, its subsidiaries and 
affiliates, and their officers, directors, employees, shareholders and agents 
in any manner likely to be harmful to them or their business, business 
reputation or personal reputation; provided that both you and the Company 
shall respond accurately and fully to any question, inquiry or request for 
information when required by legal process.

The Company will pay you all accrued salary, and all accrued and unused 
vacation earned through October 19, 1997 subject to standard payroll 
deductions and withholding.  You are entitled to these payments regardless of 
whether you sign this Agreement.  In this agreement, you are waiving any 
claim you may have to any payment under the Chief Executive Officer Bonus 
Plan in respect of 1997 as well as to any other form of compensation or 
benefit from Cadence, except as specified herein.  Both parties agree: this 
letter sets forth the entire agreement relating to the termination of your 
full-time employment and other positions with Cadence and the terms of your 
part-time employment; it supersedes any other promise, representation, or 
agreement, written or oral, relating to such subjects; and it cannot be 
amended except in writing.  If any provision of this Agreement is determined 
to be invalid or unenforceable, in whole or in part, this determination will 
not affect any other provision of this Agreement and the provision in 
question shall be modified by the court so as to be rendered enforceable.

Except with respect to obligations undertaken in this letter, you release and 
discharge Cadence and its officers, directors, shareholders, agents, 
employees, subsidiaries and affiliates from any and all liabilities and 
claims, known and unknown, arising from agreements or acts at any time prior 
to your execution of this agreement, including but not limited to any claims 
arising from your employment at Cadence, or the termination thereof, or any 
payments, severance, bonus (including but not limited to any rights under the 
1996 Chief Executive Officer Bonus Plan) or other benefits relating thereto.  
You acknowledge that the consideration for your release is in 

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addition to anything to which you are already entitled, and that you are 
knowingly and voluntarily releasing any rights you may have under the Age 
Discrimination in Employment Act.  Cadence hereby advises you that: (a) your 
release does not apply to any rights or claims that may arise after the 
execution date of this agreement; (b) you should consult with an attorney 
prior to executing this agreement; (c) you have twenty-one (21) days to 
consider this agreement (although you may choose to voluntarily execute it 
earlier); (d) you have seven days following your execution of this agreement 
to revoke the agreement; and (e) this agreement shall not be effective until 
the date upon which the revocation period has expired ("Effective Date").  
Notwithstanding anything else in this agreement, the Company agrees to defend 
and indemnify you with respect to your actions within the course and scope of 
your service as an officer, director, and employee of the Company to the 
fullest extent permitted by Section 317 of the California Corporations Code, 
including, but not limited to litigation currently pending against you in 
which you are named as an individual defendant and in which the Company is 
providing a defense.

In releasing unknown claims, you agree to waive any rights under Section 1542 
of the California Civil Code, which reads: "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." 

While it is Cadence's policy not to give releases from claims to departing 
employees, the Company is not now aware of any claims it may have against you.

You and Cadence agree that any disputes regarding the interpretation or 
enforcement of this agreement shall be decided by confidential, final and 
binding arbitration conducted by Judicial Arbitration and Mediation Services 
("JAMS") under the then-existing JAMS rules, rather than by litigation in 
court, trial by jury, administrative proceeding, or in any other forum.

If this agreement is acceptable to you, please sign in the space provided 
below and return the original to me.  I wish you all the best in your new 
ventures.

Very truly yours,

/s/ R.L. Smith McKeithen
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R.  L.  Smith McKeithen
Vice President and General Counsel


ACKNOWLEDGED AND AGREED:

 /s/ Joseph B. Costello
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Joseph B. Costello

Dated: 12/8/97
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cc: Steve Wilson

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