let R be Ring; for G, H being LeftMod of holds ZeroMap G,H is linear
let G, H be LeftMod of ; ZeroMap G,H is linear
set f = ZeroMap G,H;
reconsider G' = G, H' = H as AbGroup ;
A1:
for a being Scalar of
for x being Vector of holds (ZeroMap G,H) . (a * x) = a * ((ZeroMap G,H) . x)
ZeroMap G',H' is additive
by GRCAT_1:16;
then
for x, y being Vector of holds (ZeroMap G,H) . (x + y) = ((ZeroMap G,H) . x) + ((ZeroMap G,H) . y)
by GRCAT_1:def 13;
hence
ZeroMap G,H is linear
by A1, Def5; verum