Eskimo bowline structure of the knot was not identified by Clifford Ashley (in 1944). All of the maneuvers to tie this knot are generally in the opposite (or 'anti' direction) relative to the bowline. Dan Lehman regards the general, bowline-like structure as an 'anti-bowline' in the sense of "anti-clockwise": in that with regard to the main nipping loop, the tail on returning from forming the eye is brought through this loop in the opposite direction relative to what is done for a bowline. When this knot is ring-loaded – and the knot effectively becomes an end-to-end knot – it is effectively a
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