**SMS scnews item created by John Enyang at Mon 1 Jul 2013 1415**

Type: Seminar

Modified: Mon 1 Jul 2013 1418

Distribution: World

Expiry: 5 Jul 2013

**Calendar1: 5 Jul 2013 1100-1230**

**CalLoc1: UWS, Parramatta campus, Building EB, Room 1.32**

Auth: enyang@penyang.pc (assumed)

### UWS Colloquium

# Computing with finite semigroups

### Mitchell

###### Friday 5th July, 11:00-12:30, UWS, Parramatta campus, Building EB, Room 1.32

###### Speaker:

James Mitchell (University of St Andrews)

###### Title:

COMPUTING WITH FINITE SEMIGROUPS

###### Abstract:

In this talk I will discuss the problem of how to compute a finite semigroup. What does
it mean to `compute' a finite semigroup? It means to find structural information about
that semigroup, for example, calculating their Green's classes, size, elements, group of units,
minimal ideal, small generating sets, testing membership, finding the inverses of a regular
element, factorizing elements over the generators, and so on.

I will review what is known about computing with finite semigroups and give an overview of
recently developed functionality in the computer algebra system GAP. No prior knowledge of
computing or of semigroup theory will be assumed. Time permitting, I will demonstrate the
Semigroups software package for computing with semigroups of transformations and partial
permutations, and describe some recent theoretical advances that will allow the methods in
Semigroups to be applied to several other natural types of semigroup including monoids of
partitions.

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