English
The natural transformation from FreeMagma to FreeSemigroup commutes with map: toFreeSemigroup (map f x) = FreeSemigroup.map f (toFreeSemigroup x).
Русский
Естественная трансформация от FreeMagma к FreeSemigroup коммутирует с map: toFreeSemigroup (map f x) = FreeSemigroup.map f (toFreeSemigroup x).
LaTeX
$$$\text{toFreeSemigroup} (\text{map } f \, x) = \text{FreeSemigroup.map } f (\text{toFreeSemigroup } x)$$$
Lean4
@[to_additive]
theorem toFreeSemigroup_map (f : α → β) (x : FreeMagma α) :
toFreeSemigroup (map f x) = FreeSemigroup.map f (toFreeSemigroup x) :=
DFunLike.congr_fun (toFreeSemigroup_comp_map f) x