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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pre-existing ownership of any materials or technology provided to Corio, the results of all such development efforts set forth in this Section 13, including all intellectual property rights in any software interface coding or programs created solely by Corio during the term of this Agreement to enable the Software to operated within the Corio Servers' hosted environment ("DEVELOPMENTS"), shall be owned by Corio, unless such Developments are supported on an ongoing basis by Commerce One in which case Commerce One will retain all ownership rights, including intellectual property rights in the Developments. To the extent that Commerce One would otherwise have a claim of ownership in such Developments, Commerce One hereby assigns all rights in and to such Developments to Corio. Further, Commerce One represents and warrants that all Commerce One employees, agents, contractors or consultants that will be provided to work together with Corio have or will have signed agreements with customary terms containing confidentiality provisions and assignment of inventions ("EMPLOYEE NDA/INVENTION AGREEMENT"). Corio covenants and warrants that it will not disclose to Commerce One or its officers, directors, employees, agents, contractors or consultants any proprietary information, including without limitation any technical information related to Developments created solely by Corio under this Agreement, except upon the written authorization to do so by a Corporate Officer of Commerce One. Commerce One covenants that during the term of this Agreement, it will continue to require all Commerce One employees, agents, contractors or consultants to sign an Employee NDA/Invention Agreement and that Commerce One will furnish to Corio copies of such signed agreements upon Corio's request. Ownership of intellectual property rights to any enhancements, modifications or derivative works to the Software itself which may be developed jointly by the parties or solely by Corio shall be negotiated by the parties prior to the start of any such development work. 13.6 Independent Development: Covenant not to Sue. Nothing in this Agreement will be construed to prohibit either parties' right to independently develop the Developments contemplated above. Each party covenants that it shall not, under any circumstances, sue the other party (or its officers, directors, successors and assigns) or any of that parties' licensees, customers, or distributors ("Protected Entities") for patent infringment under any future patents or future patent rights relating to said Developments, that either party owns or controls, so long as that Protected Entity has a license from Commerce One or Corio to the Software, or to a product that is a modification of, derivative work based on, or replacement for the Software. The foregoing covenant is binding on Corio's permitted successors and assigns, and inures to the benefit of any 12 13 of Commerce One's successors and assigns, and is binding on Commerce One's permitted successors and assigns, and inures to the benefit of any of Corio's successors and assigns. 14 MISCELLANEOUS. 14.1 Assignment. Neither party may assign this Agreement or any rights or obligations hereunder, whether by operation of law or otherwise, without the prior written consent of the other party. Notwithstanding the foregoing, either party shall have the right to assign this Agreement in connection with the merger or acquisition of such party or the sale of all or substantially all of its assets related to this Agreement without such consent, except in the case where such transaction involves a direct competitor of the other party where consent of the other party will be required. Subject to the foregoing, this Agreement will bind and inure to the benefit of the parties, their respective successors and permitted assigns. Any assignment in violation of this Section 14.1 shall be null and void. 14.2 Waiver and Amendment. No modification, amendment or waiver of any provision of this Agreement shall be effective unless in writing and signed by the party to be charged. No failure or delay by either party in exercising any right, power, or remedy under this Agreement, except as specifically provided herein, shall operate as a waiver of any such right, power or remedy. 14.3 Choice of Law; Arbitration; Venue. This Agreement shall be governed by the laws of the State of California, USA, excluding conflict of laws provisions and excluding the 1980 United Nations Convention on Contracts for the International Sale of Goods. Any disputes arising out of this Agreement shall be resolved by binding arbitration in accordance with the then-current commercial arbitration rules of the American Arbitration Association ("RULES"). The arbitration shall be conducted by one (1) arbitrator appointed in accordance with the Rules in San Francisco County,
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Extract the exact clause related to "Joint Ip Ownership" from the excerpt above.

assistant: Ownership of intellectual property rights to any enhancements, modifications or derivative works to the Software itself which may be developed jointly by the parties or solely by Corio shall be negotiated by the parties prior to the start of any such development work.