Double bowline a climbing harness and provides more strength and security than the double bowline. Double bowline A double bowline (or round turn bowline) is a type of loop knot. Instead of the single turn of the regular bowline, the double bowline uses a round turn. This forms a more secure loop than a standard bowline. Though called "double bowline" by Clifford Ashley, this name is also reasonably descriptive of a different knot: the bowline on a bight. Because of this ambiguity some sources differentiate by using one of the alternate names above. And at least one other source uses the name
Signature of a knot represented as a "2g"-by-"2g" Seifert matrix "V", formula_7. The signature of the matrix formula_8, thought of as a symmetric bilinear form, is the signature of the knot "K". Slice knots are known to have zero signature. Knot signatures can also be defined in terms of the Alexander module of the knot complement. Let formula_9 be the universal abelian cover of the knot complement. Consider the Alexander module to be the first homology group of the universal abelian cover of the knot complement: formula_10. Given a formula_11-module formula_12, let formula_13 denote the formula_11-module whose underlying formula_15-module is formula_12 but where formula_17