
theorem Th88:
  for F1, F2 being non empty Graph-yielding Function st F1, F2 are_Disomorphic
  holds canGFDistinction(F1),canGFDistinction(F2) are_Disomorphic
proof
  let F1, F2 be non empty Graph-yielding Function;
  assume A1: F1,F2 are_Disomorphic;
  canGFDistinction(F1),F1 are_Disomorphic by Th87;
  then A2: canGFDistinction(F1),F2 are_Disomorphic by A1, Th40;
  F2,canGFDistinction(F2) are_Disomorphic by Th87;
  hence thesis by A2, Th40;
end;
