===== Complement =====
==== Set ====
| @#55CCEE: context     | @#55CCEE: $X,Y\in \mathfrak U$ |
| @#FFBB00: definiendum | @#FFBB00: $ x\in X \smallsetminus Y $ |
| @#55EE55: postulate   | @#55EE55: $ x\in X $ |
| @#55EE55: postulate   | @#55EE55: $ x\notin Y $ |

==== Discussion ====
=== Reference ===
Wikipedia: [[http://en.wikipedia.org/wiki/Complement_%28set_theory%29|Complement]]
==== Parents ====
=== Element of ===
[[Set universe]]
=== Context* ===
[[Set universe]]