===== Subset complement =====
==== Set ====
| @#55CCEE: context     | @#55CCEE: $Y$ |
| @#55CCEE: context     | @#55CCEE: $X\subset Y$ |

| @#FFBB00: definiendum | @#FFBB00: $ X^c \equiv Y\smallsetminus X $ |

==== Discussion ====
Notice that the notation $ X^c $ doesn't actually denote the bigger set $Y$. It is supposed to be stated or known from the context.
=== Reference ===
Wikipedia: [[http://en.wikipedia.org/wiki/Complement_%28set_theory%29|Complement]]
==== Parents ====
=== Context ===
[[Complement]]