reserve k,n,i,j for Nat;

theorem Th20:
  for G being Group holds (<*>(the carrier of G))"=<*>(the carrier of G)
proof
  let G be Group;
  len (<*>(the carrier of G))=0;
  then len ((<*>(the carrier of G))" qua FinSequence of G)=0 by Def3;
  hence thesis;
end;
