English
A variant of ContinuousAt.prodMap avoiding explicit fst/snd by using the same point (x,y).
Русский
Вариант ContinuousAt.prodMap без явного fst/snd, используя ту же точку (x,y).
LaTeX
$$$ (ContinuousAt f x) \\land (ContinuousAt g y) \\Rightarrow ContinuousAt (Prod.map f g) (x, y) $$$
Lean4
/-- A version of `ContinuousAt.prodMap` that avoids `Prod.fst`/`Prod.snd`
by assuming that the point is `(x, y)`. -/
theorem prodMap' {f : X → Z} {g : Y → W} {x : X} {y : Y} (hf : ContinuousAt f x) (hg : ContinuousAt g y) :
ContinuousAt (Prod.map f g) (x, y) :=
hf.prodMap hg