theorem Th135:
  (b <> c implies ((a,b,c) --> (x,y,z)).b = y) &
  ((a,b,c) --> (x,y,z)).c = z
  proof
    set f = (a,b) --> (x,y);
    set g = c .--> z;
    set h = (a,b,c) --> (x,y,z);
A1: c in {c} by TARSKI:def 1;
A2: dom g = {c};
   hereby assume b <> c;
    then
A3: not b in {c} by TARSKI:def 1;
    thus h.b = f.b by A3,A2,Th11
    .= y by Th63;
   end;
    thus h.c = g.c by A1,A2,Th13
    .= z by FUNCOP_1:72;
  end;
