fact: Fixpoint hasDup(A : Set)(eqd : EqDec A)(ls : list A) := match ls with | nil => false | a :: ls' => if (in_dec (EqDec_dec _) a ls') then true else (hasDup _ ls') end.
imports: FCF.Rat List Permutation Arith FCF.EqDec FCF.StdNat Bool Permutation