-Cage --- -клетка.
For a given ordered pair of integers , with and , a -regular graph with the smallest cycle length, or girth, equal to is said to be a -graph. A -cage is a -graph having the least number, , of vertices. We call the cage number of a -graph. One readily observes that -cages are cycles of length , and -cages are complete graphs of order .
The unique (3,7)-cage known as the McGee graph is an example of a cage that is not transitive. It has 24 vertices and its automorphism group has order 32.