theorem Th30:
  Ant(f^<*VERUM(Al)*>) |= Suc(f^<*VERUM(Al)*>)
proof
  let A,J,v such that
  J,v |= Ant(f^<*VERUM(Al)*>);
  Suc(f^<*VERUM(Al)*>) = VERUM(Al) by Th5;
  hence thesis by VALUAT_1:32;
end;
