proposition: Lemma dge0_muleDl x y z : 0 <= y -> 0 <= z -> (y + z) * x = y * x + z * x.
proof: Proof. by move=> *; rewrite !dual_addeE mulNe le0_muleDl ?oppe_le0 ?mulNe. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed