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 the knot, constructed from a set of curves on a Seifert surface of genus "g" which represent a basis for the first homology of the surface. This means that "V" is a 2"g" × 2"g" matrix with the property that "V" − "V" is a symplectic matrix. The "Arf invariant" of the knot is the residue of Specifically, if formula_3, is a symplectic basis for the intersection form on the Seifert surface, then where formula_5 denotes the positive pushoff of "a". This approach to the Arf invariant is due to Louis Kauffman. We define two knots to be pass equivalent