proposition: Lemma lt_succ_r n m : n < succ m <-> n<=m.
proof: Proof. unfold lt, le. rewrite compare_sub, sub_succ_r. rewrite (compare_sub n m). destruct (n-m) as [|[ | | ]|]; easy'. Qed.
imports: BinNums BinPos Pnat BinNat Bool Equalities GenericMinMax OrdersFacts ZAxioms ZProperties DecidableClass