proposition: Lemma lee_ndivr_mulr r x y : (r < 0)%R -> (y * r^-1%:E <= x) = (x * r%:E <= y).
proof: Proof. by move=> r0; rewrite muleC lee_ndivr_mull// muleC. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed