theorem Th11:
  for o being Object of A st F1 is_transformable_to F2 holds (G1*p
  )!o = G1.(p!o)
proof
  let o be Object of A;
  assume
A1: F1 is_transformable_to F2;
  then G1*F1 is_transformable_to G1*F2 by Th10;
  hence (G1*p)!o = (G1*p).o by FUNCTOR2:def 4
    .= G1.(p!o) by A1,Def1;
end;
