proposition: Lemma decomp'_none_not_unifiable sigma E: decomp' E = None -> all_terms (@lambda_free X) E -> ~ Unifies sigma E.
proof: Proof. decomp_ind; intros; simplify in *; intuition idtac. eapply decomp_none_not_unifiable in H; intuition eauto. Qed.
imports: List Lia Arith Init.Wf Morphisms Program.Program Undecidability.HOU(concon.conservativity calculus.calculus) Undecidability.HOU.unification(systemunification nth_order_unification)