Difference (from prior major revision)
(minor diff)

Changed: 10c10

The PowerSet? of any given set S forms a boolean algebra under the partial ordering "is a subset of", where 0={} and 1=S. Any subalgebra of this is called an algebra of sets.

The PowerSet? of any given set S forms a boolean algebra under the partial ordering "is a SubSet of", where 0={} and 1=S. Any subalgebra of this is called an algebra of sets, and in particular, an algebra of sets closed under arbitrary unions is called a TopOlogy.