Fixpoint Elems (l:list ad) : FSet :=
    match l with
    | nil => M0 unit
    | a :: l' => MapPut _ (Elems l') a tt
    end.

Lemma ad_list_has_circuit_stutters : forall (l0 l1 l2:list ad) (x:ad), ad_list_stutters (l0 ++ x :: l1 ++ x :: l2) = true.