Topological graph
= Topological graph
{wiki=Graph_(topology)}
A topological graph is a <CW complex> with only zero-cells and one-cells, called vertices and edges. Edge endpoints attach to vertices; loops, multiple edges and infinitely many edges are allowed. A <subgraph> in this setting is a <CW subcomplex>. A connected acyclic graph is a <tree> and is a <contractible space>.