For instance, a queue of strings would have type string TwoListQueue.queue, the empty queue is TwoListQueue.empty, and to remove the first element from a queue called q one would write TwoListQueue.remove q.
例えば、文字列のキューの型は string TwoListQueue.queue、空のキューは TwoListQueue.empty、q というキューの最初の要素を削除するには TwoListQueue.remove q と書けばよい。