===== Binary relation =====
==== Set ====
| @#55CCEE: context     | @#55CCEE: $X,Y$ |
| @#FFBB00: definiendum | @#FFBB00: $ \text{Rel}(X,Y) \equiv \mathcal{P}(X\times Y) $ |

==== Discussion ====
The set of all binary relations on $X\times Y$.

If $R$ is a binary relation, we write $x R y\equiv \langle x,y\rangle \in R$

=== Reference ===
Wikipedia: [[http://en.wikipedia.org/wiki/Binary_relation|Binary relation]]

==== Parents ====
=== Requirements ===
[[Cartesian product]], [[Power set]]