Girth (tack) sensitive horses to protect the barrel of the horse, and some styles of girth come with attached or removable sheepskin liners that perform the same function. A dressage girth, or Lonsdale girth, is shorter than the usual girths used on other saddles. This is because the dressage saddle has longer billets, to keep the buckles out from under the rider's leg, and so a shorter girth may be used. Dressage girths can be made of all the materials, and in all the styles, mentioned before, and also can be made entirely of very strong elastic. An overgirth or surcingle is
Matroid girth oracle, it is impossible to find the girth using a subexponential number of matroid queries. Similarly, for a real linear matroid of rank , with elements, described by an oracle that gives the orientation of any -tuple of elements, it requires formula_1 oracle queries to determine the girth. Computations using a girth oracle (an oracle that reports the smallest dependent subset of a given set of elements) have also been considered. Matroid girth In matroid theory, a mathematical discipline, the girth of a matroid is the size of its smallest circuit or dependent set. The cogirth of a matroid is