English
The image lifting to Finset via imageMulHom preserves multiplication: imageMulHom f acts on Finset α to Finset β by mapping s to image f s.
Русский
Перенос образа в Finset через imageMulHom сохраняет умножение: imageMulHom f переводит Finset α в Finset β, отправляя s в image f s.
LaTeX
$$imageMulHom f : Finset α → Finset β$$
Lean4
/-- Lift a `MulHom` to `Finset` via `image`. -/
@[to_additive (attr := simps) /-- Lift an `AddHom` to `Finset` via `image` -/
]
def imageMulHom [DecidableEq β] : Finset α →ₙ* Finset β
where
toFun := Finset.image f
map_mul' _ _ := image_mul _