recursion. A procedure that invokes an instance of itself, and thus can be applied repeatedly to create or analyze entities of any size: “How to put words in alphabetical order: sort the words so their first letters are in the same order as in the alphabet; then for each group of words beginning with the same letter, ignore that first letter and put the remaining parts in alphabetical order.” “A verb phrase can consist of a verb followed by a noun phrase followed by a verb phrase.”
