19. notices
all notices and statements to be given， and all payments to be made ereunder， shall be given or made at the respective addresses of the arties as set forth above unless notification of a change of address is iven in writing， and the date of mailing shall be deemed the date the otice or statement is given.
20. no joint venture
nothing herein contained shall be construed to place the parties in he relationship of partners or joint venturers， and licensee shall have o power to obligate or bind licensor in any manner whatsoever.
21. no assignment or sublicense by licensee
this agreement and all rights and duties hereunder are personal to icensee and shall not， without the written consent of licensor， be ssigned， mortgaged， sublicensed or otherwise encumbered by licensee or by peration of law. licensor may assign but shall furnish written notice of assignment.
22. no waiver， etc.
none of the terms of this agreement can be waived or modified except y an express agreement in writing signed by both parties. there are no epresentations， promises， warranties， covenants or undertakings other han those contained in this agreement， which represents the entire nderstanding of the parties. the failure of either party hereto to nforce， or the delay by either party in enforcing， any of its rights nder this agreement shall not be deemed a continuing waiver or a odification thereof and either party may， within the time provided by pplicable law， commence appropriate legal proceeding to enforce any or ll of such rights. no person， firm， group or corporation (whether ncluded in the name or otherwise) other than licensee and licensor shall e deemed to have acquired any rights by reason of anything contained in his agreement， except as provided in paragraphs 6 and 21. in witness whereof， the parties have caused this instrument to be duly xecuted as of the day and year first above written.
licensor（signature）：_________ licensee（signature）：_________