French bowline method is that the knot can be tied with one hand. A convenient way to tie a French bowline can be: French bowline Some consider that a French bowline is the same as a Portuguese bowline, i.e. a bowline with two loops that can be used as a bosun's chair. A different knot is however also known as a French bowline. This form of bowline is similar to a standard bowline but there are several loops so that there is less likelihood of damage to a delicate object secured by the bowline. As with a standard bowline, the knot cannot
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