[GAP Forum] IsMinimalNonmonomial(AlternatingGroup(5));

[Sergio Siccha]

Dear Thomas and Bill,

I have added a corresponding issue to the gap-system/gap repository, see
here:
https://github.com/gap-system/gap/issues/4452

Best,
Sergio

On 03.05.21 10:04, Thomas Breuer wrote:
> Dear Bill,
> 
> thanks for your message.
> 
> Yes, currently there is no 'IsMinimalNonmonomial' method for nonsolvable
> groups in the GAP library.
> When I wrote the code for solvable minimal nonmonomial groups (about
> thirty years ago), I was interested in van der Waall's classification of
> solvable minimal nonmonomial groups; I did not think about asking the
> question for nonsolvable groups.
> 
> I see the following ways to improve the situation.
> 
> - Implement a mehod for nonsolvable groups.
>   (Just providing some simpleminded code just in order to get an answer
>   instead of a "no method found" error message is not a good idea.
>   If someone is really interested in the question for nonsolvable groups
>   then probably the first step is to ask for minimal nonsolvable simple
>   groups, and then one looks at the monomiality condition for the subgroups
>   of these groups.)
> 
> - Change the documentation such that it says that GAP can currently answer
>   this question only for solvable groups.
>   (An example for such a solution is the function 'Omega',
>   which states: @At the moment methods exist only for abelian G and n=1.@
>   Note that this statement is not correct.)
> 
> - Give a more informative error message if the argument is a nonsolvable
>   group.
>   (Again, 'Omega' is an example where this happens.)
> 
> All the best,
> Thomas
> 
> 
> On Sun, May 02, 2021 at 12:21:57AM +0200, Bill Allombert wrote:
>> Dear Forum,
>>
>> I found
>>
>> gap> IsMinimalNonmonomial(AlternatingGroup(5));
>> Error, no method found! For debugging hints type ?Recovery from
>> NoMethodFound
>> Error, no 3rd choice method found for `IsMinimalNonmonomial' on 1
>> arguments at /usr/share/gap/lib/methsel2.g:249 called from
>>
>> Is it expected ?
>>
>> I found this while doing:
>> gap> AllGroups(Size,[1..100],IsMinimalNonmonomial,true);
>> Error, no method found! For debugging hints type ?Recovery from
>>
>> Cheers,
>> Bill.
> 
> 
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