reserve UA for Universal_Algebra,
  f, g for Function of UA, UA;
reserve I for set,
  A, B, C for ManySortedSet of I;
reserve S for non void non empty ManySortedSign,
  U1, U2 for non-empty MSAlgebra over S;

theorem Th24:
  id the Sorts of U1 in MSAAut U1
proof
  id the Sorts of U1 is_isomorphism U1, U1 by MSUALG_3:16;
  hence thesis by Def5;
end;
