definiens: means either or both of t he following, as elected by PDL pursuant to Section 2.01 hereof and set forth on Exhibit A known generally as the Cabilly patents and patent a pplications : ( a ) U.S. Patent No . 4,816,567 and the claims relati ng to chimeric antibodies found in patents or patent applications arising from divisionals, continuations or continuations - in - part of any application from which U.S. Patent No . 4,816,567 cl aims priority or any substitute applications therefor, a ny patent issued with respect to such patent application, any reissue, extension or patent term extension of any such pate nt, and any confirmation patent or registration patent or paten t of addition based on any such patent as well as the fo reign counterparts of the foregoing ( but in any event exc luding U.S.S.N. 07/205,419 and foreign counterparts thereo f ) ( ) and ( b ) any patent issuing based on U.S.S.N. 07/205,419 ( a continuation of the application maturing into U.S. Patent No