proposition: Lemma large_index_terminal {p i l r} : length P <= i -> terminal M (l, r, (basic_state (index p i))).
proof: Proof. move /not_in_iPI => Hi y /stepE [] > [] *; subst; by [| apply: Hi; eassumption]. Qed.
imports: Relation_Operators Operators_Properties Lia PeanoNat List Undecidability.StackMachines.Reductions.CM1_HALT_to_SMNdl_UB.SMX_facts Undecidability.StackMachines.Util(Nat_facts List_facts) ssreflect ssrbool ssrfun