proposition: Lemma semicomm_iter_left: forall A B (a: X A A) (b: X B B) (c: X A B), a*c <== c*b -> a#*c <== c*b#.
proof: Proof. exact (semicomm_iter_right (KA:=Dual.KleeneAlgebra)). Qed.
imports: ATBR(Common) ATBR(Classes) ATBR(Graph) ATBR(Monoid) ATBR(SemiLattice) ATBR(SemiRing)