:: deftheorem BLDef2 defines + ZMATRLIN:def 13 :
for V, W being non empty ModuleStr over INT.Ring
for f, g, b₅ being Form of V,W holds
( b₅ = f + g iff for v being Vector of V
for w being Vector of W holds b₅ . (v,w) = (f . (v,w)) + (g . (v,w)) );