proposition: Fact nat_join_right n m : m ≲ n⇡m.
proof: Proof. apply binary_le_eq_lb_mask. unfold nat_join. rewrite lb_mask_nat; auto. Qed.
imports: Arith Nat Lia List Bool Setoid Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list utils_nat bool_list gcd sums power_decomp)