<> <> <> <> RefQueue: DEFINITIONS = BEGIN <> Queue: TYPE = REF Object; Object: TYPE; <> New: PROC[nEntries: NAT _ 10] RETURNS[Queue]; <> Enqueue: PROC[queue: Queue, ref: REF ANY] RETURNS[full: BOOL]; < ref was not placed on queue>> Dequeue: PROC[queue: Queue] RETURNS[ref: REF ANY]; <> IsEmpty: PROC[queue: Queue] RETURNS[BOOL]; IsFull: PROC[queue: Queue] RETURNS[BOOL]; END.