A complete product for a finite family of subsets of a fixed
universal set
is an intersection of the
form
|
(1)
|
where
is a nonnegative integer and each
is either
or its complement
. There are
formal choices, some of which may give the empty
set. For
,
the single complete product is
. For example, the
formal complete products of
are
|
(2)
|
The nonempty complete products are pairwise disjoint and partition . Each element of the generated Boolean
algebra has a unique representation, up to order, as a union
of these nonempty complete products, with the empty set
represented by the empty union. In the following example,
denotes symmetric
difference, which agrees with union for disjoint complete
products:
|
(3)
| |||
|
(4)
| |||
|
(5)
|
(Comtet 1974, p. 186).