∀ {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]
  (I : ModelWithCorners 𝕜 E H) [inst_5 : ChartedSpace H M] (x : M), (interior (extChartAt I x).target).Nonempty