let V, W be non empty right_zeroed ModuleStr over INT.Ring ; :: thesis: for f being additiveFAF Form of V,W
for v being Vector of V holds f . (v,(0. W)) = 0
let f be additiveFAF Form of V,W; :: thesis: for v being Vector of V holds f . (v,(0. W)) = 0
let v be Vector of V; :: thesis: f . (v,(0. W)) = 0
f . (v,(0. W)) = f . (v,((0. W) + (0. W))) by RLVECT_1:def 4
.= (f . (v,(0. W))) + (f . (v,(0. W))) by BLTh27 ;
hence f . (v,(0. W)) = 0 ; :: thesis: verum