theorem :: ZMODUL01:121

for R being Ring
for V being LeftMod of R
for W1, W2 being Submodule of V holds
( ( W1 is Submodule of W2 or W2 is Submodule of W1 ) iff ex W being Submodule of V st the carrier of W = the carrier of W1 \/ the carrier of W2 ) by VECTSP_5:35;