English
If the family f is continuous in a parameter x and g is continuous at x, then the map a ↦ IccExtend h (f a) (g a) is continuous at x.
Русский
Если семейство f непрерывно по параметру x, а g непрерывна в x, то a ↦ IccExtend h (f a) (g a) непрерывна в x.
LaTeX
$$$\\forall x,\\ (\\text{ContinuousAt } f)\\text{ и } (\\text{ContinuousAt } g)\\Rightarrow \\text{ContinuousAt } (a\\mapsto IccExtend h (f a) (g a)) x.$$$
Lean4
@[simp]
theorem continuous_IccExtend_iff {f : Icc a b → β} : Continuous (IccExtend h f) ↔ Continuous f :=
isQuotientMap_projIcc.continuous_iff.symm