consider x, y, z being object such that

A1: ( x in X & y in Y & z in Z & f = <*x,y,z*> ) by FINSEQ_3:125;

thus ( f . 1 is Relation-like & f . 1 is Function-like ) by A1, FINSEQ_1:45; :: thesis: verum

A1: ( x in X & y in Y & z in Z & f = <*x,y,z*> ) by FINSEQ_3:125;

thus ( f . 1 is Relation-like & f . 1 is Function-like ) by A1, FINSEQ_1:45; :: thesis: verum