theorem Th36:
  for V being RealLinearSpace, W being Subspace of V, L being
Linear_Compl of W holds W + L = the RLSStruct of V & L + W = the RLSStruct of V
proof
  let V be RealLinearSpace, W be Subspace of V, L be Linear_Compl of W;
  V is_the_direct_sum_of W,L by Th35;
  hence W + L = the RLSStruct of V;
  hence thesis by Lm1;
end;
