take
ZeroMap V,W
; ( ( for x, y being Vector of V holds (ZeroMap V,W) . (x + y) = ((ZeroMap V,W) . x) + ((ZeroMap V,W) . y) ) & ( for a being Scalar of K
for x being Vector of V holds (ZeroMap V,W) . (a * x) = (J . a) * ((ZeroMap V,W) . x) ) )
thus
( ( for x, y being Vector of V holds (ZeroMap V,W) . (x + y) = ((ZeroMap V,W) . x) + ((ZeroMap V,W) . y) ) & ( for a being Scalar of K
for x being Vector of V holds (ZeroMap V,W) . (a * x) = (J . a) * ((ZeroMap V,W) . x) ) )
by Lm18, Lm19; verum