import OAI.Geometry.Arnold.Degeneracy namespace OAI noncomputable section open scoped BigOperators ContDiff open scoped Topology NNReal open Set Filter namespace ArnoldCounterexample /-- The Hamiltonian counterexample, with the complete fixed set, the lower bound for all smooth functions, and a genuine nonzero quotient-tangent eigenvector. -/ theorem main : ∃ φ : Q3 ≃ Q3, IsHamiltonian φ ∧ (fixedSet φ).encard = 3 ∧ (3 : ℕ∞) < 4 ∧ 4 ≤ criticalNumber ∧ HasDegenerateFixedPoint φ := by exact ⟨Construction.mainEquiv, Construction.main_isHamiltonian, Construction.main_fixed_encard, by norm_num, four_le_criticalNumber, Construction.main_degenerate⟩ end ArnoldCounterexample end end OAI