system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
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this Agreement. 15.4 Relationship of the Parties. D2 and LICENSEE are independent contractors under this Agreement. Nothing contained in this Agreement is intended to, nor is it to be construed so as to, constitute D2 and LICENSEE as partners or joint ventures with respect to this Agreement. Employees of any party remain employees of said party and shall at not time be considered agents of or to be obligated to render a fiduciary duty to the other party. 15.5 Modification. No alteration, amendment, waiver, cancellation or any other change in any term or condition of this Agreement shall be valid or binding on any party unless the same shall have been mutually assented to in writing by both parties. 15.6 Waiver. The failure of any party of enforce at any time any of the provisions of this Agreement, or the failure to require at any time performance by the other parties of any of the provisions of this Agreement, shall in no way be construed to be a present or future waiver of such provision, nor in any way affect the right of any party to enforce each and every such provision thereafter. The express waiver by any party of any provision, condition or requirement of this agreement shall not constitute a waiver of any future obligation to comply with such provision, condition or requirement. Software License D2 Technologies, Inc. and Maintenance Agreement August 4, 1997 CONFIDENTIAL 17 15.7 Assignment. This Agreement shall be binding upon and shall inure to the benefit of the parties hereto and their respective successors and assigns. No party may assign any of its rights, obligations or privileges (except by operation of law or other corporate reorganization) hereunder without the prior written consent of the other party, which shall not be unreasonable withheld, provided, that any party shall have the right to assign its rights, obligations and privileges hereunder to a successor in business or an acquirer of all or substantially all of its business or assets to which this Agreement pertains without obtaining the consent of the other party. 15.8 Notices. Any notice required or permitted to be given by any party under this Agreement shall be in writing, shall be addressed to the President of D2, or to the President of LICENSEE, and shall be personally delivered or set by certified or registered letter, or by telecopy confirmed by registered or certified letter, to the receiving party at its address first set forth above, or such new address as may from time to time be supplied hereunder by the receiving party. Notices will be deemed effective upon receipt. 15.9 Force Majeure. Notwithstanding anything else in this Agreement, no default, delay or failure to perform on the part of any party shall be considered a breach of this Agreement if such default, delay or failure to perform is shown to be due to causes beyond the reasonable control of the party charged with a default, including, but not limited, causes such as strikes, lockouts or other labor disputes, riots, civil disturbances, actions or inactions of governmental authorities or suppliers, epidemics, war, embargoes, were weather, fire, earthquakes, acts god, acts of the public enemy or nuclear disasters; provided, that for the duration of such force majeure the party charged with such default must continue to use all reasonable efforts to overcome such force majeure. 15.10 Entire Agreement. The terms and conditions contained in this Agreement constitute the entire agreement between the parties and supersede all previous agreements and understandings, whether oral or written, between the parties hereto with respect to the subject matter hereof. IN WITNESS WHEREOF, the parties hereto have caused this agreement to be signed by duly authorized officers or representatives as of the date first above written. "LICENSEE" D2 TECHNOLOGIES, INC. - --------------------------------- ----------------------------------- BY: /s/ Dick Swee BY: /s/ David Y. Wong ----------------------------- ------------------------------- Software License D2 Technologies, Inc. and Maintenance Agreement August 4, 1997 CONFIDENTIAL 18 PRINT NAME: Dick Swee PRINT NAME: David Y. Wong --------------------- ----------------------- TITLE: VP Engineering TITLE: President -------------------------- ------------------------------ Software License D2 Technologies, Inc. and Maintenance Agreement August 4, 1997 CONFIDENTIAL 19 EXHIBIT A LICENSED TECHNOLOGY SPECIFICATION Basic Services: The Basics Services algorithm group shall include the following list of standard D2 products with LICENSEE required modifications as specified in the attached Specification and the Contract for Products and Services, dated August 6, 1997: DTMF Detection and Removal Algorithm 5007-54A Universal Tone Detection Algorithm 50030-54A Multifrequency Tone Detection Algorithm 50028-54A Tone Generation Algorithm 50015-54A Voice
"""

Extract the exact clause related to "Covenant Not To Sue" from the excerpt above.

assistant: Not found.