reserve x,y,z,X for set,
  T for Universe;

theorem Th4:
  for R be RelStr, T be non empty 1-sorted, p be Element of T
  holds the carrier of ConstantNet(R,p) = the carrier of R
proof
  let R be RelStr, T be non empty 1-sorted, p be Element of T;
  the RelStr of ConstantNet(R,p) = the RelStr of R by Def5;
  hence thesis;
end;
