Editing Complement (set theory) (section)

=== Examples ===
* Assume that the universe is the set of [[integer]]s. If {{mvar|A}} is the set of odd numbers, then the complement of {{mvar|A}} is the set of even numbers. If {{mvar|B}} is the set of [[Multiple (mathematics)|multiples]] of 3, then the complement of {{mvar|B}} is the set of numbers [[Modular arithmetic|congruent]] to 1 or 2 modulo 3 (or, in simpler terms, the integers that are not multiples of 3).
* Assume that the universe is the [[standard 52-card deck]]. If the set {{mvar|A}} is the suit of spades, then the complement of {{mvar|A}} is the [[Union (set theory)|union]] of the suits of clubs, diamonds, and hearts. If the set {{mvar|B}} is the union of the suits of clubs and diamonds, then the complement of {{mvar|B}} is the union of the suits of hearts and spades.
*When the universe is the [[Universe (mathematics)|universe of sets]] described in formalized [[set theory]], the absolute complement of a set is generally not itself a set, but rather a [[proper class]].  For more info, see [[universal set]].