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.