[GAP Forum] ClassNames and the Atlas

Simon Nickerson simonn at for.mat.bham.ac.uk
Wed Apr 27 17:36:14 BST 2005


Dear GAP forum,

Is there any way of getting GAP to use the names of conjugacy classes as
described in the Atlas of Finite Groups (and the Web Atlas)? The command

CN := ClassNames(CT, "ATLAS");

works when CT is the character table of a simple group, but when it is an
almost-simple group, there is disagreement. For example, the conjugacy
classes of elements of order 8 in HS.2 are called:

Atlas:   8A   8BC  8D   8E
GAP:     8A   8B   8C   8D

(i.e. GAP labels the classes alphabetically, and the Atlas labels them
according to how the corresponding classes in the simple group HS fuse
together). This might cause problems, because there are two conjugacy
classes of HS.2 which might conceivably be called '8D'.

If there is no way to get GAP to use Atlas conventions, does anyone have a
list of the examples where the two systems disagree?

Thanks,

-- 
| Simon Nickerson            http://web.mat.bham.ac.uk/S.Nickerson
| simonn at maths.bham.ac.uk                    School of Mathematics
|                                     The University of Birmingham
|_________________________________   Edgbaston, Birmingham B15 2TT




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