proposition: Lemma size_le p : 2^(size p) <= p~0.
proof: Proof. induction p as [p IHp|p IHp|]; simpl; try rewrite pow_succ_r; try easy. apply mul_le_mono_l. apply le_lteq; left. rewrite xI_succ_xO. apply lt_succ_r, IHp. Qed.
imports: BinNums Eqdep_dec EqdepFacts RelationClasses Morphisms Setoid Equalities Orders OrdersFacts GenericMinMax PeanoNat BinPosDef