theorem Th3:
  id the carrier of G is Element of Aut G
proof
  id the carrier of G is Homomorphism of G, G by GROUP_6:38;
  then consider h such that
A1: h = id the carrier of G;
  rng h = the carrier of G by A1,RELAT_1:45;
  then h is onto;
  hence thesis by A1,Def1;
end;
