English
For f: G → E, s ⊆ E, x ∈ G, and iso: E ≃L[𝕜] F, HasFDerivWithinAt (iso ∘ f) ((iso : E →L[𝕜] F) ∘ f') s x is equivalent to HasFDerivWithinAt f f' s x.
Русский
Для f: G → E, s ⊆ E, x ∈ G и iso: E ≃L[𝕜] F, HasFDerivWithinAt (iso ∘ f) ((iso : E →L[𝕜] F) ∘ f') s x эквивалентно HasFDerivWithinAt f f' s x.
LaTeX
$$$HasFDerivWithinAt (iso \circ f) ((iso : E →L[𝕜] F) \circ f') s x \iff HasFDerivWithinAt f f' s x$$$
Lean4
theorem comp_differentiable_iff {f : G → E} : Differentiable 𝕜 (iso ∘ f) ↔ Differentiable 𝕜 f :=
by
rw [← differentiableOn_univ, ← differentiableOn_univ]
exact iso.comp_differentiableOn_iff