let K be Ring; :: thesis: for V being LeftMod of K
for W2, W1, W3 being Subspace of V holds W2 + (W1 /\ W3) c= (W1 + W2) /\ (W2 + W3)
let V be LeftMod of K; :: thesis: for W2, W1, W3 being Subspace of V holds W2 + (W1 /\ W3) c= (W1 + W2) /\ (W2 + W3)
let W2, W1, W3 be Subspace of V; :: thesis: W2 + (W1 /\ W3) c= (W1 + W2) /\ (W2 + W3)
W2 + (W1 /\ W3) is Subspace of (W1 + W2) /\ (W2 + W3) by VECTSP_5:34;
hence W2 + (W1 /\ W3) c= (W1 + W2) /\ (W2 + W3) by Def7; :: thesis: verum