proposition: Lemma star_destruct_left_old A B: forall (a: X A A) (b c: X A B), b+a*c <== c -> a#*b <== c.
proof: Proof. intros; transitivity (a#*c). rewrite <- H; semiring_reflexivity. apply star_destruct_left. rewrite <- H at -1; auto with algebra. Qed.
imports: ATBR(Common) ATBR(Classes) ATBR(Graph) ATBR(Monoid) ATBR(SemiLattice) ATBR(SemiRing)