U.W. Bangor - School of Informatics - Mathematics Preprints 1997
Computational discrete algebra
97.05 : ALP, M. & WENSLEY, C.D.
Enumeration of cat1-groups of low order
Abstract:In this paper we describe a share package XMOD of functions for computing with finite, permutation crossed modules, cat1-groups and their morphisms, written using the GAP group theory programming language. The category XMod of crossed modules is equivalent to the category Cat1 of cat1-groups and we include functions emulating the functors between these categories. The monoid of derivations of a crossed module X, and the corresponding monoid of sections of a cat1-group C, are constructed using the Whitehead multiplication. The Whitehead group of invertible derivations, together with the group of automorphisms of X are used to construct the actor crossed module of X which is the automorphism object in XMod. We include a table of the 350 isomorphism classes of cat1-structures on groups of order at most 30.
Published in:IJAC 10 (2000) 407-424.
97.32 : ALP, M.
GAP, Crossed modules, cat1-groups
Published in:U W Bangor PhD thesis (April 1997)