English
There is a canonical map to the implicit function from HasStrictFDerivAt, giving a derivative of the implicit function with kernel restriction.
Русский
Существует каноническое отображение к неявной функции из HasStrictFDerivAt, задающее производную неявной функции в ограничении ядра.
LaTeX
$$$ hf.to_implicitFunction hf' hker : HasStrictFDerivAt (hf.implicitFunction f f' hf' hker (f a)) (\ker f').subtypeL 0 $$$
Lean4
/-- `HasStrictFDerivAt.implicitFunction` sends `(z, y)` to a point in `f ⁻¹' z`. -/
theorem map_implicitFunction_eq (hf : HasStrictFDerivAt f f' a) (hf' : range f' = ⊤) :
∀ᶠ p : F × ker f' in 𝓝 (f a, 0), f (hf.implicitFunction f f' hf' p.1 p.2) = p.1 :=
haveI := FiniteDimensional.complete 𝕜 F
map_implicitFunctionOfComplemented_eq ..