English
If α is an additive semigroup, then Holor α ds forms an additive semigroup under the pointwise addition.
Русский
Если α образует добавочную полугруппу, то Holor α ds образует добавочную полугруппу при точечном сложении.
LaTeX
$$$\text{If } α \text{ is an additive semigroup, then }\mathrm{Holor}(α, ds)\text{ with } (x+y)(t)=x(t)+y(t)\text{ is an additive semigroup.}$$$
Lean4
instance [AddSemigroup α] : AddSemigroup (Holor α ds) :=
Pi.addSemigroup