fact: Fixpoint nth_default A (d:A) (n:nat) (l:list A) {struct l} : A := match l with | nil => d | x::l' => match n with | 0 => x | S n' => nth_default d n' l' end end.
imports: Coq.Classes.Morphisms TLC(LibTactics LibLogic LibReflect LibOperation LibProd LibOption LibNat LibInt LibWf LibMonoid LibRelation)