import Mathlib import OAI.Combinatorics.MatchingPSD.Model namespace OAI namespace PerfectMatchingPSD noncomputable def matchingPoint {n : ℕ} (M : PerfectMatching n) : Edge n → ℝ := by classical exact fun e => if e ∈ M.1 then 1 else 0 noncomputable def matchingPolytope (n : ℕ) : Set (Edge n → ℝ) := convexHull ℝ (Set.range (matchingPoint (n := n))) def HasAffineLift (n r : ℕ) : Prop := ∃ (L : AffineSubspace ℝ (Matrix (Fin r) (Fin r) ℝ)) (T : Matrix (Fin r) (Fin r) ℝ →ᵃ[ℝ] (Edge n → ℝ)), T '' {X | X ∈ L ∧ X.PosSemidef} = matchingPolytope n end PerfectMatchingPSD end OAI