Editing Cofiniteness (section)

==Other examples==

===Product topology===
The [[product topology]] on a product of topological spaces <math>\prod X_i</math> has [[Basis (topology)|basis]] <math>\prod U_i</math> where <math>U_i \subseteq X_i</math> is open, and cofinitely many <math>U_i = X_i.</math>

The analog without requiring that cofinitely many factors are the whole space is the [[box topology]].

===Direct sum===
The elements of the [[direct sum of modules]] <math>\bigoplus M_i</math> are sequences <math>\alpha_i \in M_i</math> where cofinitely many <math>\alpha_i = 0.</math>

The analog without requiring that cofinitely many summands are zero is the [[direct product]].