Uni knot Uni knot The uni knot is a multi purpose fishing knot that can be used for attaching the fishing line to the arbor of a reel, for joining lines, and for attaching lures, snaps, and swivels. The knot, shown with three passes, was published in 1944 under the name gallows knot (#1121) in The Ashley Book of Knots. Ashley notes that it is actually an alternate arrangement of the multiple overhand noose. His diagram shows how the knot can be manipulated into the more familiar form. This knot is also called the Duncan loop, after Norman Duncan who developed it
Signature of a knot Signature of a knot The signature of a knot is a topological invariant in knot theory. It may be computed from the Seifert surface. Given a knot "K" in the 3-sphere, it has a Seifert surface "S" whose boundary is "K". The Seifert form of "S" is the pairing formula_1 given by taking the linking number formula_2 where formula_3 and formula_4 indicate the translates of "a" and "b" respectively in the positive and negative directions of the normal bundle to "S". Given a basis formula_5 for formula_6 (where "g" is the genus of the surface) the Seifert form can be