A feasible point can be rounded to a parent vertex preserving all closed-face memberships
ProvedHirsch.feasible_point_has_face_preserving_parent_vertexextreme-faceshirsch-conjecturepath-repairpolyhedra
For a compact parent and any family of closed extreme faces, every feasible point has a parent extreme vertex that lies in every supplied face containing the point; the face family need not be finite.
Preamble
import Mathlib import Mathlib.Analysis.Convex.KreinMilman import Definitions.Def_Hirsch_model open scoped BigOperators RealInnerProductSpace open Set Hirsch
Formal statement
namespace Hirsch
theorem feasible_point_has_face_preserving_parent_vertex
{d : ℕ} {ι : Type*} (P : Set (EuclideanSpace ℝ (Fin d)))
(F : ι → Set (EuclideanSpace ℝ (Fin d)))
(hP : IsCompact P) (hF : ∀ i, IsExtreme ℝ P (F i))
(hclosed : ∀ i, IsClosed (F i))
(x : EuclideanSpace ℝ (Fin d)) (hx : x ∈ P) :
∃ v, v ∈ extremePoints ℝ P ∧ ∀ i, x ∈ F i → v ∈ F i := by sorry
end HirschSource
Kernel-verified theorem from jjoshua2/prove2me-work PR #48/#50.