Dear GAP forum, It seems that GAP can find representatives for all systems of minimal blocks of imprimitivity for an arbitrary group action, but all blocks only for a permutation group (and there seems no easy way to get all maximal blocks).
I have tried to get around this as follows. G is a group acting on O (which is actually an orbit on 2-subsets of [1..n]). I do the following: GG:=Action(G,O,OnSets); BB:=AllBlocks(GG); B:=List(BB,x->List(x,y->O[y])); This assumes that the Action maps each element of O to its position in the list, and I can't find a guarantee to this effect in the manual. Can I rely on this? Thanks for any advice. Peter Cameron. -- This email address will stop working sometime soon. Please use the address pj...@st-andrews.ac.uk instead. _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
