OAI/Geometry/SurfaceImmersion/Whitney/CrosscapArcNeighborhood.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

The compact half-arc contains a whole neighborhood of its endpoint in the compactified double curve.

  1. lemma OAI.ClosedSurfaceR4.FiniteOrderSmoothing.unorderedPair_mem_square line 16
  2. theorem OAI.ClosedSurfaceR4.FiniteOrderSmoothing.crosscap_arc_contains_neighborhood line 23