English
The space of continuous linear maps M →L[R] M₂ is an additive commutative group under pointwise addition.
Русский
Множество непрерывных линейных отображений M →L[R] M₂ образует коммутативную группу под точечным сложением.
LaTeX
$$$\text{Hom}_{\text{cont}}(M,M_2) = M \to_L[R] M_2 \text{ with } (f+g)(x)=f(x)+g(x).$$$
Lean4
instance addCommGroup : AddCommGroup (M →SL[σ₁₂] M₂)
where
__ := ContinuousLinearMap.addCommMonoid
neg := (-·)
sub := (· - ·)
sub_eq_add_neg _ _ := by ext; apply sub_eq_add_neg
nsmul := (· • ·)
zsmul := (· • ·)
zsmul_zero' f := by ext; simp
zsmul_succ' n f := by ext; simp [add_smul, add_comm]
zsmul_neg' n f := by ext; simp [add_smul]
neg_add_cancel _ := by ext; apply neg_add_cancel