proposition: Fact mb_is_tuple_dec t n (v : vec _ n) : { t ≋ ⦉v⦊ } + { ~ t ≋ ⦉v⦊ }.
proof: Proof. Proof using Xfin Rdec. revert t; induction v as [ | x n v IHv ]; intros t. + apply (fol_quant_sem_dec fol_fa); auto; intro. apply (fol_bin_sem_dec fol_imp); auto. + simpl; apply (fol_quant_sem_dec fol_ex); auto; intro. apply (fol_bin_sem_dec fol_conj); auto. Qed.
imports: List Arith Nat Lia Max Wellfounded Coq.Setoids.Setoid Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.FOL.TRAKHTENBROT(notations fol_ops fo_sig fo_terms fo_logic)