
theorem Th6:
  for L being non empty 1-sorted, N being non empty NetStr over L,
  f being Function of N, N holds the carrier of N * f = the carrier of N
proof
  let L be non empty 1-sorted, N be non empty NetStr over L, f be Function of
  N, N;
  the RelStr of N * f = the RelStr of N by Def2;
  hence thesis;
end;
