∀ {𝕜 : Type u_1} {E : Type u_2} {M : Type u_3} {H : Type u_4} [inst : NontriviallyNormedField 𝕜]
  [inst_1 : NormedAddCommGroup E] [inst_2 : NormedSpace 𝕜 E] [inst_3 : TopologicalSpace H] [inst_4 : TopologicalSpace M]
  (f : OpenPartialHomeomorph M H) {I : ModelWithCorners 𝕜 E H} {X : Type u_8} [inst_5 : TopologicalSpace X] {g : M → X}
  {s : Set M} {x : M},
  ContinuousWithinAt (g ∘ ↑(f.extend I).symm) (↑(f.extend I).symm ⁻¹' s ∩ Set.range ↑I) (↑(f.extend I) x) ↔
    ContinuousWithinAt (g ∘ ↑f.symm) (↑f.symm ⁻¹' s) (↑f x)