Stable belt Stable belt A stable belt is an item of uniform used in the armed forces of Denmark, the United Kingdom and other Commonwealth countries. Gymnastic belts are similar coloured belts used in Brazil and Lebanon. The stable belt originates from when cavalrymen would place the surcingle around the waist when cleaning the stables and tending to their horses. In the 1950s they spread to all branches of the armed forces, adding a splash of colour and individuality to the drab khaki working uniforms. Initially they were resisted by many senior officers, who saw them as too individualistic, but they soon
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