let GF be non empty right_complementable associative well-unital distributive Abelian add-associative right_zeroed doubleLoopStr ; :: thesis: for V being non empty right_complementable VectSp-like Abelian add-associative right_zeroed VectSpStr of GF
for u, v being Element of V
for W being Subspace of V st u in W & v in W holds
u + v in W
let V be non empty right_complementable VectSp-like Abelian add-associative right_zeroed VectSpStr of GF; :: thesis: for u, v being Element of V
for W being Subspace of V st u in W & v in W holds
u + v in W
let u, v be Element of V; :: thesis: for W being Subspace of V st u in W & v in W holds
u + v in W
let W be Subspace of V; :: thesis: ( u in W & v in W implies u + v in W )
assume ( u in W & v in W ) ; :: thesis: u + v in W
then A1: ( u in the carrier of W & v in the carrier of W ) by STRUCT_0:def 5;
reconsider VW = the carrier of W as Subset of V by Def2;
VW is linearly-closed by Lm2;
then u + v in the carrier of W by A1, Def1;
hence u + v in W by STRUCT_0:def 5; :: thesis: verum