Q = insert(Q,x)
i1 : Q = priorityQueue {1,2,3} o1 = PriorityQueue{...4...} o1 : PriorityQueue
i2 : insert(Q,0) o2 = PriorityQueue{...4...} o2 : PriorityQueue
i3 : insert(Q,4) o3 = PriorityQueue{...4...} o3 : PriorityQueue
i4 : min Q o4 = 0
The priority queue Q is mutable and is altered by insert. Q is also the output of the function.