English
If g: X × Y → Z is continuous, e: W → X is continuous, f: W → Y is continuous, then w ↦ g(e(w), f(w)) is continuous.
Русский
Если g: X×Y→Z непрерывна, e:W→X непрерывна и f:W→Y непрерывна, то w↦g(e(w),f(w)) непрерывно на W.
LaTeX
$$Continuous g → Continuous e → Continuous f → Continuous (λ w, g (e w, f w))$$
Lean4
theorem comp₂ {g : X × Y → Z} (hg : Continuous g) {e : W → X} (he : Continuous e) {f : W → Y} (hf : Continuous f) :
Continuous fun w => g (e w, f w) :=
hg.comp <| he.prodMk hf