Description of the Graph

Below you find a description of the singular graph of this spine:

Graph code :

	1	V9	V1
	2	V9	V1
	3	V9	V6
	4	V9	V6
	5	V1	V7
	6	V1	V7
	7	V6	V5
	8	V6	V3
	9	V5	V3
	10	V7	V4
	11	V5	V4
	12	V7	V2
	13	V3	V2
	14	V4	V2
	15	V5	V8
	16	V3	V8
	17	V4	V8
	18	V2	V8

The first column lists the edges, given by their numbers. V9, V1, etc. are names of vertices. The first line says that edge 1 is goes from vertex V9 to vertex V1, the second -- that edge 2 does the same, and so on. In particular, the edges are oriented.