theorem
  for U0 be with_const_op Universal_Algebra for U1,U2 be SubAlgebra of
  U0 holds Constants(U1) = Constants(U2)
proof
  let U0 be with_const_op Universal_Algebra,U1,U2 be SubAlgebra of U0;
  Constants(U0) = Constants(U1) by Th6;
  hence thesis by Th6;
end;
