theorem
  <NAT,+,0> = multLoopStr(#NAT,addnat,0#)
proof
  set N = <NAT,+,0>;
  the multMagma of N = <NAT,+> & the_unity_wrt op(N) = un(N) by Def22,Th17;
  hence thesis by Th40,Th43;
end;
