Writhe
Also called the Twist Number. The sum of crossings 
of a Link 
,
where
defined to be 
if the overpass slants from top left to bottom right or bottom left to topright and 
is the set of crossings of an oriented Link. If a Knot 
is Amphichiral, then
(Thistlethwaite). Letting Lk be the Linking Number of the two components of a ribbon, Tw be theTwist, and Wr be the writhe, then
(Adams 1994, p. 187).See also Screw, Twist
References
Adams, C. C. The Knot Book: An Elementary Introduction to the Mathematical Theory of Knots. New York: W. H. Freeman, 1994.
- Elliptic Hyperboloid
- Elliptic Integral
- Elliptic Integral of the First Kind
- Elliptic Integral of the Second Kind
- Elliptic Integral of the Third Kind
- Elliptic Integral Singular Value
- Elliptic Integral Singular Value k1
- Elliptic Integral Singular Value k2
- Elliptic Integral Singular Value k3
- Ellipticity
- Elliptic Lambda Function
- Elliptic Logarithm
- Elliptic Modular Function
- Elliptic Paraboloid
- Elliptic Partial Differential Equation
- Elliptic Plane
- Elliptic Point
- Elliptic Pseudoprime
- Elliptic Rotation
- Elliptic Theta Function
- Elliptic Torus
- Elliptic Umbilic Catastrophe
- Ellison-Mendès-France Constant
- Elongated Cupola
- Elongated Dipyramid