theorem Th11:
  (Omega).V + W = the RLSStruct of V & W + (Omega).V = the RLSStruct of V
proof
  the carrier of W c= the carrier of V by RLSUB_1:def 2;
  then W + (Omega).V = the RLSStruct of V by Lm3;
  hence thesis by Lm1;
end;
