fact: Fixpoint fexp A (f : A -> A) n := match n with 0 => (fun x => x) | S n => fcompose f (fexp f n) end.
imports: Arith micromega.Lia Setoid IndefiniteDescription ClassicalChoice HahnBase HahnList HahnEquational HahnRewrite HahnRelationsBasic HahnSets HahnNatExtra HahnListBefore HahnWf HahnSorted HahnTotalExt