Girth (tack) often used in addition to a regular leather girth. Made of leather or nylon with an elastic insert (for racing), the overgirth completely encircles the horse around belly and the saddle's seat. It is used by stockmen, eventers, polo players, in flat racing, and by steeplechase jockeys to provide more security in holding the saddle in place. Some girths (those used on jumpers and eventers) have a belly guard (or stud guard), to protect the belly from being stabbed by horseshoe studs as the animal tucks his legs up underneath him over a tall obstacle. The traditional western cinch was
Girth (graph theory) repeating the Mycielskian construction used to form the Grötzsch graph produces triangle-free graphs of arbitrarily large chromatic number. Paul Erdős was the first to prove the general result, using the probabilistic method. More precisely, he showed that a random graph on vertices, formed by choosing independently whether to include each edge with probability has, with probability tending to 1 as goes to infinity, at most cycles of length or less, but has no independent set of size Therefore, removing one vertex from each short cycle leaves a smaller graph with girth greater than in which each color class of a