step-hen 0.0.3

A rudimentary implementation of Stephen's procedure for inverse monoids.

README - step_hen - by James D. Mitchell and Maria Tsalakou

step_hen contains a rudimentary implementation of three algorithms of J. B. Stephen and Andrew Cutting for finitely presented monoids and inverse monoids in python3. These algorithms can be used to check equality of a fixed word with any other word in a finitely presented monoid, or inverse monoid, and to compute the structure of a finitely presented inverse monoid.

The implementation is rudimentary because it lacks many obvious optimisations and improvements, it is intended as a simple proof of concept.

The algorithms are described in the following:

• J. B. Stephen, “Presentations of inverse monoids”, J. Pure Appl. Algebra, 63 (1990) 81–112; http://dx.doi.org/10.1016/0022-4049(90)90057-O

• J. B. Stephen, “Applications of automata theory to presentations of monoids and inverse monoids”, The University of Nebraska - Lincoln (1987); https://digitalcommons.unl.edu/dissertations/AAI8803771

• Andrew Cutting, “Todd-Coxeter methods for inverse monoids”, PhD thesis, University of St Andrews (2001) http://hdl.handle.net/10023/15052

Installation

You can install step_hen using pip:

pip install step_hen