Theorem isOpen_extChartAt_target

Modification history

2025-02-04 15:13
Mathlib/Geometry/Manifold/IsManifold/Basic.lean
chore(Geometry/Manifold/IsManifold): split out material on extended charts (#21219) …
Modified isOpen_extChartAt_targetView on Github →
2024-02-22 00:33
Mathlib/Geometry/Manifold/SmoothManifoldWithCorners.lean
feat: Lemmas about `(extChartAt I x).target` being open if we're boundaryless (#10840) …
Added isOpen_extChartAt_targetView on Github →