# Chapter2Combinatorics

¶Enumerative Combinatorics

Enumerative combinatorics

Date back to the first prehistorics

Who counted; relations

Like sets' permutations

To them were part cult, part folklorics.

Throughout this book we will be counting things. In this chapter we will outline some of the tools that will help us count.

Counting occurs not only in highly sophisticated applications of mathematics to engineering and computer science but also in many basic applications. Like many other powerful and useful tools in mathematics, the concepts are simple; we only have to recognize when and how they can be applied.