# Absolute Complement

The complement $$A^\complement$$ of a set $$A$$ is the set of all things that are not in $$A$$. Put simply, the complement is its opposite.

Where $$U$$ denotes the universe, $$A^\complement = U \setminus A$$. That is, $$A^\complement$$ is the Relative complement of $$U$$ and $$A$$.