French bowline 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 tighten. Pressure is distributed over a wider area than in the case of a standard bowline. The main advantage of this
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