Queue implementations are commonly based on insertion order as in first-in, first-out (FIFO) queues or last-in, first-out queues (LIFO queues are also known as stacks).

I cannot delve him to the root.

That is mentally—outsidely, but not insidely. You have not relaxed down through your body at all.

a distributive numeral, such as Latin bini (two by two)