On Wed, Dec 18, 2019 at 11:21:11PM +0000, Hulpke,Alexander wrote: > Dear Forum, Dear Keith, > > > Is there something wrong with my installation? > No. Both issues are in the released code. > > You encounter two different issues where particular cases have not yet been > implemented. As they occur only for comparatively large groups I felt the > functionality for simple groups was valuable as-is without having to wait for > these cases to be sorted out. Both have to do with triality automorphisms, > and would be somewhat fiddly to get right. > (If anyone has code or ready descriptions for these cases, I would be happy > to include it for future releases.) > > > GRP[208]:=[208,65784756654489600,"O",[9,3]] > > Error, mixed triality not yet done at > > /home/dennis/GAP4.10.1/gap-4.10.1/grp/simple.gi:859 called from > > EFactors( Gcd( 2, (par[2] - 1) ) ^ 2, expo, 6 ) at > > /home/dennis/GAP4.10.1/gap-4.10.1/grp/simple.gi:1047 called from > > DataAboutSimpleGroup( id ) at > > DataAboutSimpleGroups calculates (beyond what > IsomorphismTypeInfoFiniteSimpleGroup does) — among other things — the > structure of the outer automorphism group. > For type D4 this involves also the triality automorphism, and the current > code does not yet consider its interaction with field automorphisms — thus > the error message. > > > GRP[211]:=[211,67671071404425216,"U",[3,127]] > > Error, Can't do yet at > > /home/dennis/GAP4.10.1/gap-4.10.1/grp/simple.gi:577 called from > > CallFuncList( SimpleGroup, b ) at > > This would be the Chevalley group of type 3D4(4). The simple groups code does > not construct groups as Chevalley groups, but as classical groups of from > existing libraries. I am not aware of an existing library that contains a > representation of 3D4(4). > (The same holds for any larger fields and certain other large exceptional > groups).
Does anyone has GAP code to build a representation of 3D4(q) (for any q=p^k) ? We'd like to have it for a project where we build a library of distance-regular graphs. Thanks Dima > > Regards, > > Alexander Hulpke > > > > /home/dennis/GAP4.10.1/gap-4.10.1/grp/simple.gi:696 called from > > 0 = cnt mod len at SimpleGroupList.gap:83 called from > > <function "ListSimpleShortNoL2">( <arguments> ) > > called from read-eval loop at *stdin*:5 > > you can 'quit;' to quit to outer loop, or > > you can 'return;' to continue > > brk> return; > > Error, Variable: 'g' must have an assigned value in > > if s <> fail and not HasName( g ) then > > SetName( g, s ); > > fi; at /home/dennis/GAP4.10.1/gap-4.10.1/grp/simple.gi:629 called from > > CallFuncList( SimpleGroup, b ) at > > /home/dennis/GAP4.10.1/gap-4.10.1/grp/simple.gi:696 called from > > 0 = cnt mod len at SimpleGroupList.gap:83 called from > > <function "ListSimpleShortNoL2">( <arguments> ) > > called from read-eval loop at *stdin*:5 > > you can 'return;' after assigning a value > > brk> > > > > > > > > > > > > Ok, I tried the NOSL2 option, and ran into another problem. > > > > > > Keith > > > > > > > > _______________________________________________ > > Forum mailing list > > Forum@gap-system.org > > https://mail.gap-system.org/mailman/listinfo/forum > > _______________________________________________ > Forum mailing list > Forum@gap-system.org > https://mail.gap-system.org/mailman/listinfo/forum _______________________________________________ Forum mailing list Forum@gap-system.org https://mail.gap-system.org/mailman/listinfo/forum
