[GAP Forum] a suggestion on the design of GAP

Benjamin Sambale benjamin.sambale at gmail.com
Tue Aug 18 06:34:23 BST 2020


Dear GAP people,

let me start with a little puzzle: Which of the following commands 
behaves differently?

AllIrredSolMatrixGroups
AllIrreducibleSolubleMatrixGroups
AllIrreducibleSolvableGroups
AllIrreducibleSolvableMatrixGroups

For a long time I have been thinking that they all were synonyms. Until 
recently, I observed that AllIrreducibleSolvableGroups is different. It 
takes slightly different arguments (Characteristic instead of Field) and 
has a limited range. For instance:

AllIrreducibleSolvableGroups(Dimension,8,Characteristic,2);
#W  AllIrreducibleSolvableGroups: n = 8 outside range of library
Error, all Dimension arguments outside range of library

AllIrreducibleSolvableMatrixGroups(Dimension,8,Field,GF(2)); #works

Now every time I want to list matrix groups I have to rethink what the 
"correct" command was. I can't think of a situation where 
AllIrreducibleSolvableGroups is superior to the other commands.
So my suggestion is to remove this function. It would also help me 
memorizing to have just a single command instead of many synonyms (this 
also improves tab-completion on the command line).

Best wishes,
Benjamin



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