All Foundations and Algebraic Topology

Branches that study shape through continuity and that translate it into algebra. An entry belongs here when its cited source describes open sets, continuity and compactness, or the assignment of groups and other algebraic invariants to spaces so that spaces can be told apart. It does not belong here when the branch concerns manifolds, embeddings or knots, which are covered by the geometric topology group. The group follows the usual course in the subject, which begins with point-set ideas and moves to homotopy and homology.