## Category Theory

There are two approaches to category theory, most books, such as those under 'expert' below assume quite a wide knowledge of mathematics. They give lots of examples from different structures to help the reader to 'abstract out' the categorical concepts.

#### Introduction

The following two books, both co-authored by F. William Lawvere, are aimed at relative newcomers to mathematics. Although they are not trivial and I think they are useful for a wide range of readers.

Conceptual Mathematics - This is a book about category theory that does not assume an extensive knowledge over a wide area of mathematics. The style of the book is a bit quirky though. |

Sets for Mathematics - This is a book about sets from category theory point of view. |

#### Expert

Categorical Theory - This book is a general introduction to the subject, a bit easier than the Saunders Mac Lane book but still very theoretical. |

## Category Theory and Logic

Introduction to Higher Order Categorical Logic - Lambek & Scott - Relates lambda calculus to higher order logic and cartesian closed categories. |

## Category Theory and Type Theory

Categorical Logic and Type Theory - This book is about logic, type theory and category theory. It assumes the reader is familiar with category theory concepts such as adjunctions, limits and CCCs. |