proposition: Lemma mul_lt_mono_l p q r : q<r <-> p*q < p*r.
proof: Proof. unfold lt. rewrite mul_compare_mono_l. apply iff_refl. Qed.
imports: BinNums Eqdep_dec EqdepFacts RelationClasses Morphisms Setoid Equalities Orders OrdersFacts GenericMinMax PeanoNat BinPosDef