Subsemigroups of virtually free groups: finite Malcev presentations and testing for freeness (2008)
This paper shows that, given a finite subset X of a finitely generated virtually free group F, the freeness of the subsemigroup of F generated by X can be tested algorithmically. (A group is...
Presentations for the simple groups (2007)
Colin M. Campbell, George Havas, Alexander Hulpke, Edmund F. Robertson, North Haugh, North Haugh
We prove that the simple group L3(5) which has order 372000 is efficient by providing an efficient presentation for it. This leaves one simple group with order less than one million, S4(4) which has...
Date: Signature of candidate: (2005)
Alan James Cain, Name Alan, J. Cain, Name Alan, J. Cain, Name Prof, ...
To many absent friends.
Irreducible Cyclic Presentations of the Trivial Group (2003)
Havas, George, Robertson, Edmund F.
We produce families of irreducible cyclic presentations of the trivial group. These families comprehensively answer questions about such presentations asked by Dunwoody and by Edjvet, Hammond, and...
Applications of computational tools for finitely presented groups (1994)
Havas, George, Robertson, Edmund F.
Computer based techniques for recognizing finitely presented groups are quite powerful. Tools available for this purpose are outlined. They are available both in stand-alone programs and in more...