[sci.math] Knot equivalence via Reidemeister moves

orourke@whatever.cs.jhu.edu (Joseph O'Rourke) (03/20/91)

Has anyone implemented a program that searches for a sequence
of Reidemeister moves to convert one knot into another,
or one knot into the unknot?  Any references would be appreciated.
Thanks!

arshad@cs.ed.ac.uk (Arshad Mahmood) (03/23/91)

In article <10453@cs.jhu.edu> orourke%sophia@cs.umass.edu (Joseph O'Rourke) writes:
>Has anyone implemented a program that searches for a sequence
>of Reidemeister moves to convert one knot into another,
>or one knot into the unknot?  Any references would be appreciated.

I can think of no article specifically related to using Reidmeister moves,
but an article by Thistlewaite in "Aspects of topology: in memory of Hugh 
Dowker 1912-1982" comes to mind. It discusses an algorithm for knot 
classification.

It shouldn't be very difficult to implement such a program, since there are
only 4 (I think !) moves to perform. There would naturally be a state-space
explosion, but I suspect this is inevitable. You could cut the search 
space down quite a lot by using any of the well known polynomials, to see if 
the knots are equivalent at all. A good place to start for this is the paper by
Louis Kauffman (it's in the AMS series, I don't have the exact reference at
hand (shame on me!) if you don't know it then get in touch and I will send the
proper reference.)

I hope this is some help, best of luck !

Title: Aspects of topology: in memory of Hugh Dowker 1912-1982
London Mathematical Society Vol. 93
1985

A. Mahmood
LFCS 
Edinburgh University
Scotland