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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Contractor with copies of such rules and policies or has advised Contractor of the existence of such rules and policies. (d) Company may request changes that affect the scope or duration of the Services relating to any Statement of Work, including changes in the Specifications and changes in the deliverables to be delivered. Company acknowledges that any change in Specifications may result in changes to estimated fees and estimated timeline for creation of deliverables. Company also may request a change in the Schedule without changing the scope of the Services relating to the applicable Statement of Work. In either case, the parties shall negotiate in good faith a reasonable and equitable adjustment in the applicable fees, Schedule and Specifications. Contractor shall continue work pursuant to the existing Statement of Work, and shall not be bound by any change requested by Company, until such change has been accepted in writing by Contractor. (e) The obligations of Company in connection with a particular engagement shall be set forth in the applicable Statement of Work. Company agrees to perform such obligations in accordance with, and subject to, such Statement of Work. Company acknowledges that when a Statement of Work provides that Company's personnel are to work with Contractor's personnel in connection with an engagement, Company's failure to assign Company personnel having skills commensurate with their role with respect to such engagement could adversely affect Contractor's ability to provide the Services. Page 3 of 10 (f) To the extent Contractor provides any third party materials and products Contractor acknowledges that it shall be solely responsible for ensuring the functionality and specifications of such third party materials and products used in performing Services under this Agreement. 2. TERM. The term of this Agreement shall begin on the date hereof and shall continue until terminated by either party pursuant to Paragraph 6 hereof. 3. CONTRACTOR'S COMPENSATION. (a) During the term of this Agreement, Company agrees to compensate Contractor as set forth in each Statement of Work. Contractor will be compensated on a time and materials. In addition, Company shall reimburse Contractor its actual out-of-pocket expenses as reasonably incurred by Contractor in connection with its performance of the Services as negotiated in each Statement of Work. (b) Contractor shall bill Company as set forth in the relevant Statement of Work. Each invoice submitted by Contractor will provide supporting detail for the Services invoiced, including, to the extent applicable to a particular engagement, the dates of Services and hours worked at the applicable rate by Statement of Work. Invoices shall also include receipts or other supporting detail concerning related expenses within the billing cycle. Contractor reserves the right to change rates with 30 days notice to Company. (c) All fees, charges and other amounts payable to Contractor hereunder do not include any sales, use, excise, value added or other applicable taxes, tariffs or duties, payment of which shall be the sole responsibility of Company (excluding any applicable taxes based on Contractor's net income or taxes arising from the independent contractor relationship between Contractor and its personnel). In the event that such taxes, tariffs or duties are assessed against Contractor, Company shall reimburse Contractor for any such amounts paid by Contractor or provide Contractor with valid tax exemption certificates with respect thereto. 4. OWNERSHIP OF MATERIALS RELATED TO SERVICES; ACCEPTANCE. (a) The parties agree that all drawings, documents, designs, models, inventions, computer programs, computer systems, data, computer documentation and other tangible materials authored or prepared by Contractor for Company as the work product required by a Statement of Work (collectively, the "Works"), are the property of Company to the extent that such Works were created by Contractor for Company over a time period for which Company has been invoiced and said invoice has been paid. Contractor agrees to render, at Company's sole cost Page 4 of 10 and expense, all reasonably required assistance to Company to protect the rights herein above described, including executing other documents as requested by Company. (b) Company acknowledges that Contractor provides consulting and development services to other clients, and agrees that nothing in this Agreement shall be deemed or construed to prevent Contractor from delivering on such business. In particular, Company agrees that, notwithstanding anything to the contrary set forth herein: (i) as part of Contractor's provision of the Services hereunder, Contractor may utilize its own proprietary works of authorship, that have not been created specifically for Company, including without limitation software, methodologies, tools, specifications, drawings, sketches, models, samples, records and documentation, as well
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Extract the exact clause related to "Irrevocable Or Perpetual License" from the excerpt above.