
theorem
  for G1 being _Graph, G2, G3 being removeDParallelEdges of G1
  holds G3 is G2-Disomorphic
proof
  let G1 be _Graph, G2, G3 be removeDParallelEdges of G1;
  G1 is G1-Disomorphic by Th53;
  hence thesis by Th170;
end;
