Amendment; Waivers. This Agreement shall not be amended, altered or modified except by an instrument in writing duly executed by each of the parties hereto and, with respect to Apple Ten, with the prior approval of the Company Special Committee, and, with respect to Parent, with the prior approval of the Parent Board. No delay or failure on the part of any party hereto in exercising any right, power or privilege under this Agreement shall impair any such right, power or privilege or be construed as a waiver of any default or any acquiescence thereto. No waiver shall be valid against any party hereto, unless made in writing and signed by the party against whom enforcement of such waiver is sought, and then only to the extent expressly specified therein.