Spanish bowline complicated knot however and if not properly tightened, it can slip. A fireman's chair knot is another double loop knot which is more practical, easier to tie and less prone to slipping although it lacks the elegance of a Spanish bowline. Spanish bowline The Spanish bowline is a double loop knot that can be used to lift a person. For a conscious person, each loop is placed around a leg and the person holds onto the standing part of the rope. This knot can serve as a makeshift Bosun's chair. For an unconscious person one loop is placed around the
Mutation (knot theory) endpoints of the tangle. There is also a rotation that results from composition of the reflections. A mutation replaces the original tangle by a tangle given by any of these operations. The result will always be a knot and is called a mutant of "K". Mutants can be difficult to distinguish as they have a number of the same invariants. They have the same hyperbolic volume (by a result of Ruberman), and have the same HOMFLY polynomials. Mutation (knot theory) In the mathematical field of knot theory, a mutation is an operation on a knot that can produce different knots.