Every side of a triangle is divided into three edges: this is , the cycle with nine vertices. A, B and C are original vertices. D is the first internal vertex on B–C. Every observer reports the minimum distance to the two endpoints of an edge: . The graph is fixed throughout this investigation.

Four different things appear on screen and are drawn differently: a vertex (a letter in a circle; filled when it is an observer), an edge (a code such as AC2 with a line mark), a distance (a number of links, read on the horizontal axis) and a multiplicity (how many observers report that distance: the height of a bar, written ×2).

A distance multiset keeps each distance and its multiplicity, without attaching observer names. A histogram displays exactly the same multiset: horizontal position is distance; height is the number of observers reporting it. Tracing a bar temporarily restores names to explain its origin; those names are not part of the multiset.

An observer set resolves the edges when every two distinct edges have different complete multisets. On this triangle, checking all 512 selections shows that three observers are the fewest that work and that no selection of seven or more vertices works. The paper cites for every cycle with . These finite checks do not prove anything about larger graphs.