reserve R for Ring,
  V for RightMod of R,
  W,W1,W2,W3 for Submodule of V,
  u,u1, u2,v,v1,v2 for Vector of V,
  x,y,y1,y2 for object;

theorem
  for W being strict Submodule of V holds W /\ W = W
proof
  let W be strict Submodule of V;
  the carrier of W = (the carrier of W) /\ the carrier of W;
  hence thesis by Def2;
end;
