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:
"""
believes a [***] is likely to occur but it has not yet been [***], RevMed may, no more than [***] per Calendar Year, request for the Parties to discuss such potential [***] and Sanofi's intended plans with respect to [***], provided that, for clarity, such discussion shall not be deemed to accelerate the timeframes specified above in Section 12.2(a). 12.3 Effects of Expiration or Termination. (a) General. Upon termination or expiration of this Agreement with respect to any particular Product or country, all rights and obligations of the Parties under this Agreement with respect to such Product or country shall cease except as otherwise set forth in this Section 12.3 or elsewhere in this Agreement, but, for clarity, such termination or expiration shall not affect the Parties' rights and obligations under this Agreement with respect to the other Products or countries. (b) Effect of Expiration. Upon expiration of this Agreement, the licenses granted to Sanofi under Section 3.1 will become fully paid up, royalty free, perpetual and irrevocable. (c) Effect of Termination by Sanofi for Convenience, Change of Control or Termination by RevMed for Sanofi's Material Breach, Insolvency, Competing Product, or Cessation of [***]. Upon the termination of this Agreement by Sanofi pursuant to Section 12.2(a)(i) (Termination by Sanofi for Convenience) or Section 12.2(a)(ii)A (Termination by Sanofi for Change of Control of RevMed) or by RevMed pursuant to Section 12.2(b) (Termination for Material Breach), 12.2(c) (Termination for Insolvency), 12.2(d) (Termination for Competing Product of Sanofi) or 12.2(e) (Termination for Sanofi's Decision to Cease [***] of Product), the following provisions shall apply: (i) License to Sanofi. All licenses and other rights granted to Sanofi under the RevMed Licensed Technology shall terminate (except as necessary to permit Sanofi to perform its surviving obligations under this Article XII) and all rights thereunder shall revert to RevMed. (ii) Licenses. A. License Grants. 1. RevMed License to SHP2 Inhibitors. Sanofi shall, effective upon any such termination of this Agreement, and hereby does, grant to RevMed [***], under all [***], and [***], to [***]. Notwithstanding the foregoing, [***] shall not include [***], and [***] shall include [***] (to the extent [***]). 2. RevMed License to Practice Certain Combinations. Sanofi shall, effective upon any such termination of this Agreement, and hereby does, grant to RevMed [***], under [***], and [***] (but excluding [***]). For the avoidance of doubt, [***] licensed under this Section 12.3(c)(ii)(A)(2) do not [***]. 60 Source: REVOLUTION MEDICINES, INC., S-1, 1/17/2020 3. Sanofi License to Practice Certain Combinations. [***] RevMed shall, effective upon any such termination of this Agreement, and hereby does, grant to Sanofi [***], under [***], and [***]. For the avoidance of doubt, [***] licensed under this Section 12.3(c)(ii)(A)(3) do not [***]. If Sanofi [***], Sanofi shall so notify RevMed in writing, and [***]. B. Third Party Restrictions. If the rights licensed to RevMed pursuant to subsection A are sublicensed to RevMed under an agreement between Sanofi and a Third Party, then Sanofi shall so notify RevMed within [***] after the effective date of termination of this Agreement, and the foregoing licenses shall be subject to the applicable provisions of such Third Party agreement (including any applicable payment obligations to the extent arising from the exercise of RevMed's practice of its license under subsection A). RevMed shall have the right to terminate all or any portion of the rights granted to it under subsection A, upon written notice to Sanofi. C. Royalties. If this Agreement is terminated in its entirety or with respect to one or more Products, other than by RevMed pursuant to Section 12.2(b) (Termination for Material Breach) or 12.2(c) (Termination for Insolvency), RevMed shall pay to Sanofi on a Product-by-Product basis royalties on sales of terminated Products (such Products, which for the purpose of clarity shall not include any Non-SHP2 Product, hereinafter referred to as "Termination Products"), calculated based on worldwide Net Sales (as such term is applied mutatis mutandis to RevMed and including sales in the U.S.) by RevMed and its Affiliates and Sublicensees of such Termination Products as follows: [***]. RevMed shall pay Sanofi such royalties until the earlier of (x) expiration of the Post-Termination Royalty Term therefor and (y) a Change of Control of Sanofi. Upon any termination of this Agreement, RevMed shall pay to Sanofi any amounts owed to Third Parties under license agreements to which Sanofi is a party that grant Sanofi a license under such Third Party's Patent Rights or Know-How that is sublicensed to RevMed pursuant to Section 12.3(c)(ii)A, unless RevMed declines
"""

Extract the exact clause related to "Irrevocable Or Perpetual License" from the excerpt above.

assistant: Upon expiration of this Agreement, the licenses granted to Sanofi under Section 3.1 will become fully paid up, royalty free, perpetual and irrevocable.