
theorem Th2:
  for A,B being transitive with_units non empty AltCatStr, F,F1,
  F2 being Functor of A,B holds F is_transformable_to F1 & F1
  is_transformable_to F2 implies F is_transformable_to F2
proof
  let A,B be transitive with_units non empty AltCatStr,
  F,F1,F2 be Functor of A,B;
  assume
A1: F is_transformable_to F1 & F1 is_transformable_to F2;
  let a be Object of A;
  <^F.a,F1.a^> <> {} & <^F1.a,F2.a^> <> {} by A1;
  hence thesis by ALTCAT_1:def 2;
end;
