theorem
  for A being strict Universal_Algebra holds A = 1-Alg MSAlg A
proof
  let A be strict Universal_Algebra;
  the carrier of A in {the carrier of A} by TARSKI:def 1;
  then the carrier of A in rng the Sorts of MSAlg A by FUNCOP_1:8;
  hence thesis by Def12;
end;
