English
If M has Zero and N is an AddGroup, then there is a natural integer action on AddMonoidHom M N by a • f with (a • f)(m) = a • f(m).
Русский
Если M имеет ноль и N является AddGroup, то существует целочисленное действие на AddMonoidHom M N: (a·f)(m)=a·f(m).
LaTeX
$$$\mathbb{Z}\text{-action on }(M\to^+ N), \; (a\cdot f)(m)=a\cdot f(m).$$$
Lean4
instance instIntSMul [AddZeroClass M] [AddCommGroup N] : SMul ℤ (M →+ N) where
smul a
f :=
{ toFun := a • f
map_zero' := by simp [zsmul_zero]
map_add' x y := by simp [zsmul_add] }