English
The continuous map mulLeft x is the map y ↦ x y, giving left multiplication by x as a continuous endomorphism.
Русский
Карта mulLeft x задаёт отображение слева умножения на x, непрерывна как эндоморфизм на X.
LaTeX
$$$\\text{ContinuousMap.mulLeft}(x) : X \\to X$, $y \\mapsto x y$$$
Lean4
@[to_additive (attr := fun_prop)]
theorem smul (hf : ContinuousOn f s) (hg : ContinuousOn g s) : ContinuousOn (fun x => f x • g x) s := fun x hx =>
(hf x hx).smul (hg x hx)