struct qelem {
 struct qelem *q_forw;
 struct qelem *q_back;
 char q_data[];
};

insque(elem, pred)
struct qelem *elem, *pred;

remque(elem)
struct qelem *elem;
 DESCRIPTION
 Insque and 
 remque manipulate queues built from doubly linked lists. Each
element in the queue must in the form of ``struct qelem''.
 Insque inserts 
 elem in a queue immediately after 
 pred ;  remque removes an entry
 elem  from a queue.
 "SEE ALSO
``VAX Architecture Handbook'', pp. 228-235.