let K be Ring; :: thesis: for V being LeftMod of K
for W1, W2 being Subspace of V holds
( W1 c= W1 + W2 & W2 c= W1 + W2 )
let V be LeftMod of K; :: thesis: for W1, W2 being Subspace of V holds
( W1 c= W1 + W2 & W2 c= W1 + W2 )
let W1, W2 be Subspace of V; :: thesis: ( W1 c= W1 + W2 & W2 c= W1 + W2 )
( W1 is Subspace of W1 + W2 & W2 is Subspace of W1 + W2 ) by VECTSP_5:11;
hence ( W1 c= W1 + W2 & W2 c= W1 + W2 ) by Def7; :: thesis: verum