#+title: relations
- tags :: [[file:20200708122545-category_theory.org][category theory]]
- source :: [[file:literature/20210117123933-act4e_session_2_connection.org][ACT4E - Session 2 - Connection]]

A relation is a special type of [[file:20210116154952-category.org][category]]. A relation is a subset of the
Cartesian product $X \times Y$.