Triple bowline a "seat" in which the injured person can be raised or lowered safely. The full triple bowline is also used in rescue situations with the third loop passed around the waist or torso. The triple bowline is often mistakenly referred to as the double bowline. The double bowline is in fact a bowline tied on a single strand with the nipping loop doubled up, and only has one loop. Triple bowline The triple bowline knot is a variation of the bowline knot. The knot can be applied to emergency situations, such as mountain rescue. The name comes from the three
Arf invariant of a knot if they are related by a finite sequence of pass-moves, which are illustrated below: (no figure right now) Every knot is pass-equivalent to either the unknot or the trefoil; these two knots are not pass-equivalent and additionally, the right- and left-handed trefoils are pass-equivalent. Now we can define the Arf invariant of a knot to be 0 if it is pass-equivalent to the unknot, or 1 if it is pass-equivalent to the trefoil. This definition is equivalent to the one above. Vaughan Jones showed that the Arf invariant can be obtained by taking the partition function of a signed planar