
theorem
  for x,y,z being set st z <> [<*x,y*>, xor2] holds x in InputVertices
  GFA3AdderStr(x,y,z) & y in InputVertices GFA3AdderStr(x,y,z) & z in
  InputVertices GFA3AdderStr(x,y,z)
proof
  let x,y,z be set such that
A1: z <> [<*x,y*>,xor2];
  set S0 = GFA0AdderStr(x,y,z);
  GFA3AdderStr(x,y,z) = S0;
  hence thesis by A1,Th27;
end;
