Field of sets
In mathematics a field of sets is a pair where
is a set and
is an algebra over
i.e., a non-empty subset of the power set of
closed under the intersection and union of pairs of sets and under complements of individual sets. In other words,
forms a subalgebra of the power set Boolean algebra of
. (Many authors refer to
itself as a field of sets. The word "field" in "field of sets" is not used with the meaning of field from field theory.) Elements of
are called points and those of
are called complexes and are said to be the admissible sets of
.