proposition: Fact nat_join_assoc n m k : n⇡(m⇡k) = n⇡m⇡k.
proof: Proof. apply equal_lb_mask_equiv; unfold nat_join. repeat rewrite nat_lb_nat. rewrite lb_join_assoc; 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)