Changes
/* Rotor-routing */
The rotor-routing game proceeds as follows: A vertex can be routed if it has a positive number of chips. If a vertex is routed, the rotor edge of the vertex is augmented to the next edge in the cyclic order, and a chip is taken from the vertex, and is placed on the head of the new rotor edge.
Holroyd et. al <ref name="HLMPPW08"/> defined a group action of the [[picard group of a graph|picard group]] on the set of spanning [[arborescencesarborescence|in-arborescencearborescences]] of a graph with the help of rotor-routing. The computation of this group action is [[Complexity of computing the rotor-router action|open]].
==References==
