English
If h has MDifferentiableWithinAt f s x and an eventual equality with f, then MDifferentiableWithinAt f1 s x holds.
Русский
Если у h есть MD differentiableWithinAt f s x и f1 эквивалентна f почти повсюду в окрестности x, то MDifferentiableWithinAt f1 s x выполняется.
LaTeX
$$$MDifferentiableWithinAt\ I I'\ f\ s\ x\ f' \land (f_1 =^\! [𝓝[s] x] f) \Rightarrow MDifferentiableWithinAt\ I I'\ f_1\ s\ x$$$
Lean4
theorem congr_of_eventuallyEq (h : MDifferentiableWithinAt I I' f s x) (h₁ : f₁ =ᶠ[𝓝[s] x] f) (hx : f₁ x = f x) :
MDifferentiableWithinAt I I' f₁ s x :=
(h.hasMFDerivWithinAt.congr_of_eventuallyEq h₁ hx).mdifferentiableWithinAt