OAI/Geometry/SurfaceImmersion/Whitney/CrosscapComposedDirection.lean

GitHub source file

1 declarations, 0 contain sorry, 0 declared as axioms

A source coordinate change preserves the regular direction zero of the standard crosscap when the vertical direction is its kernel.

  1. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.crosscap_composed_direction_bijective line 13