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:
"""
1 EXHIBIT 10.3 SOFTWARE LICENSE AND MAINTENANCE AGREEMENT This Software license and maintenance agreement ("Agreement") is entered into effective as of August 4, 1997 (the "Effective Date") by and between D2 Technologies, Inc., a California corporation with offices at 104 West Anapamu Street, Santa Barbara, CA 93101 ("D2"), and Summa Four Inc., a Delaware corporation with offices at 25 Sundial Avenue, Manchester, New Hampshire 03103-7251 ("LICENSEE"). WHEREAS, D2 has previously developed certain software and designs capable of performing certain voice processing functions; WHEREAS, LICENSEE is developing a product which requires certain software functions and designs capable of performing certain voice processing functions; WHEREAS, D2 desires to license to LICENSEE certain of its software technology for use in connection with Licensee's products: WHEREAS, D2 is further willing to provide certain maintenance and support services to LICENSEE in relation to such software technology; NOW THEREFORE, in consideration of the mutual promises and covenants contained herein, the parties agree as follows: 1. DEFINITIONS 1.1 "Licensed Technology" shall mean software licensed to LICENSEE by D2 as listed in Exhibit A. 1.2 "DSP" shall mean digital signal processing. 1.3 "Runtime License Fee" shall have the meaning set forth in Article 2.2(iii). 1.4 "Specifications" shall mean D2's specifications of the Licensed Technology which are attached hereto as Exhibit A. 1.5 "Update" shall mean a new release of a software product which typically includes bug fixes and/or minor feature changes, but does not include substantial new functionality. Software License D2 Technologies, Inc. and Maintenance Agreement August 4, 1997 CONFIDENTIAL 2 1.6 "New Version" in this Agreement shall mean a new release of Licensed Technology that provides significant performance enhancements, including new releases of software product optimized for different members of the same DSP processor family which is based on the same core architecture and instruction set. 1.7 "Defect" shall mean any failure of Licensed Technology to meet the Specification as a result of a material failure (including an error or "bug" that is material) of the Licensed Technology. "Material" is defined as priority A, B, and C in Article 6.3. 1.8 "Source Code" shall mean all computer programming instructions relating to a software product in a form readable by humans and typically prepared by a programmer. Source Code includes associated procedural code, comments, utilities, tools, notes, data diagrams and related and supporting technical documentation. 1.9 "Object Code" shall mean software code resulting from the translation or processing of Source Code by a computer into machine language or intermediate code, which thus is in a form that would not be convenient to human understanding of the program logic, but which is appropriate for execution or interpretation by a computer. 1.10 "Licensed Source Code" shall mean Source Code for Licensed Technology. 1.11 "Licensee Product" shall mean the product being developed by LICENSEE as described in Exhibit B, which utilizes Licensed Technology. LICENSEE shall own all rights, title and interest in Licensee Product. D2 shall have no rights to Licensee Product. 1.12 "End User" shall mean a person or business entity that purchases, leases or otherwise properly obtains the right to use or distribute a Licensee Product directly from LICENSEE or through one or more intermediaries. 2. LICENSED TECHNOLOGY 2.1 Ownership. Subject to the rights granted to LICENSEE in this Agreement, D2 owns all right, title and interest in and to the Licensed Technology. Notwithstanding the foregoing, LICENSEE shall retain all right, title and interest in and to modifications to the Licensed Source Code made by LICENSEE pursuant to the license in Article 2.2 below, subject always to D2's ownership rights in the underlying Licensed Technology. Software License D2 Technologies, Inc. and Maintenance Agreement August 4, 1997 CONFIDENTIAL 3 2.2 License to LICENSEE. (i) Subject to the terms and conditions of this Agreement, D2 hereby grants LICENSEE a perpetual non-exclusive, worldwide license, to use Licensed Technology in Object Code format only as an incorporated part of the Licensee Product. For this purpose, LICENSEE may also modify, create derivative works, of and reproduce and have reproduced the Licensed Technology, and to develop, use, market and distribute (directly or through third parties) Licensed Technology, or modifications or derivative works of the Licensed Technology created by or for LICENSEE. (ii) In consideration for the right to modify, develop and completely own derivative works of the Licensed Technology set forth in Article 2.2 (i) above, LICENSEE shall pay D2 a license fee (the "Development License Fee") as set forth in Exhibit C. Final acceptance testing shall be completed by the parties according to Article
"""

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

assistant: (i) Subject to the terms and conditions of this Agreement, D2 hereby grants LICENSEE a perpetual non-exclusive, worldwide license, to use Licensed Technology in Object Code format only as an incorporated part of the Licensee Product.