theorem Th65:
  cod p1 = c & cod p2 = c implies (x1,x2)-->(p1,p2) is
  Injections_family of c,{x1,x2}
proof
  assume
A1: cod p1 = c & cod p2 = c;
  cods ((x1,x2)-->(p1,p2)) = (x1,x2) --> (cod p1,cod p2) by Th7
    .= {x1,x2} --> c by A1,FUNCT_4:65;
  hence thesis by Def16;
end;
