fact: Definition below_in (n: nat): list nat -> Prop := fun bnats => forall n', n' < n <-> In n' bnats.
imports: Coq(FunctionalExtensionality Arith Lia) Coq(Arith.Peano_dec Arith.Compare_dec) Coq(Relations.Relation_Operators) Coq(List) Chapar(Predefs)