Bowline goes he." An alternative "lightning method" can also be used; see this animation. There is a potential with beginners to tie what is known as an Eskimo bowline. This faulty knot stems from an incorrect first step while tying the rabbit hole. If the loop is made backwards so that the end of the rope (the bitter end) is on the bottom, the resulting knot will be sideways. The final loop of a sideways bowline will slip. This makes it particularly dangerous in the case of an inexperienced sailor, who, in addition to having an insecure knot, is also less
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