Interleaved parameter sets are minimal nonfaces of the original moment inequalities
ProvedHirsch.interleaved_moment_minimal_nonfacesLet a assign distinct real parameters to m original labels. Choose k+1 pairs of labels l_i,r_i with a(l_i)<a(r_i), and a(r_i)<a(l_j) whenever i<j. In dimension 2k form the original mean-centered moment inequalities row_i(x)<=1, with the average over ALL m original labels. The sets L={l_i} and R={r_i} each have exactly k+1 labels, are disjoint, and are both incompatible: every feasible point leaves at least one L row and one R row strictly slack. Conversely EVERY proper subset S of either L or R has an actual feasible point making exactly the S rows tight and every other ORIGINAL row strictly slack. Thus both are minimal nonfaces of this explicit inequality system. The proof derives the left/right barycentric signs by pairing factors, applies the accepted barycentric polynomial obstruction, and constructs all proper-subset witnesses through the accepted squared-root polynomial theorem. No sign classification, infeasibility witness, proper-face oracle, or precomputed minimal-nonface catalogue is an assumption. The zero-dimensional case k=0 is included as a statement about rows. The theorem does not assert that all displayed rows are genuine facets in every degenerate case, count the full family of such sets, establish boundedness/full-dimensionality, or prove a graph-diameter bound.
import Mathlib open scoped BigOperators
theorem Hirsch.interleaved_moment_minimal_nonfaces (k m : ℕ) (a : Fin m → ℝ) (ha : Function.Injective a)
(l r : Fin (k+1) → Fin m)
(hpair : ∀ i, a (l i) < a (r i))
(hsep : ∀ i j, i < j → a (r i) < a (l j)) :
let row : (Fin (2*k) → ℝ) → Fin m → ℝ := fun x i =>
∑ j : Fin (2*k),
(a i ^ (j.val+1) - (∑ z, a z ^ (j.val+1)) / (m : ℝ)) * x j
let L : Finset (Fin m) := Finset.univ.image l
let R : Finset (Fin m) := Finset.univ.image r
L.card = k+1 ∧ R.card = k+1 ∧ Disjoint L R ∧
(∀ x : Fin (2*k) → ℝ, (∀ i, row x i ≤ 1) →
(∃ i ∈ L, row x i < 1) ∧ (∃ i ∈ R, row x i < 1)) ∧
∀ S : Finset (Fin m), (S ⊂ L ∨ S ⊂ R) →
∃ x : Fin (2*k) → ℝ, ∀ i, row x i ≤ 1 ∧ (row x i = 1 ↔ i ∈ S) := by sorry