fact: Fixpoint In_queue_before (d : data) (f1 : data -> bool) (q : queue data) {struct q} : Prop := match q with | empty => True | input d' q' => if eq_bool_dec (f1 d') then False else d' = d \/ In_queue_before d f1 q' end.
imports: DistributedReferenceCounting.machine4.machine DistributedReferenceCounting.machine4.cardinal DistributedReferenceCounting.machine4.comm