proposition: Fact nat_join_comm n m : n⇡m = m⇡n.
proof: Proof. apply lb_mask_equiv_equal. rewrite lb_join_comm; 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)