The flavor paths connecting two external vertices are represented by a single vertex.

It and the tetrahedron are the only known polyhedra in which every possible line segment connecting two vertices forms an edge of the polyhedron.

That is, we form a vertex for each disk, and connect two vertices by an edge whenever the corresponding disks have non-empty intersection.

An edge (a set of two elements) is drawn as a line connecting two vertices, called endpoints or (less often) endvertices.

A common extension is to hypergraphs, where an edge can connect more than two vertices.

Edges directly (not cut by other chords) connecting two exterior vertices.

Edges connecting two interior vertices.

Each edge of the vertex figure exists on or inside of a face of the original polytope connecting two alternate vertices from an original face.

A bosonic propagator is represented by a wavy line connecting two vertices (- -).

A fermionic propagator is represented by a solid line (with an arrow in one or another direction) connecting two vertices, (- -).