Hmm I have to retract this last post.Using for i in range(0, len(R)): w = W(R[i])
still triggers the bug. Best, Michel On Thursday, February 5, 2026 at 12:57:16 PM UTC+1 Michel VAN DEN BERGH wrote: > On Thursday, February 5, 2026 at 12:15:21 PM UTC+1 wrote: > > As a workaround, I think that explicitly converting the gap list returned > by libgap.RightTransversal(W, G) into a python list helps. I.e., > > list(libgap.RightTransversal(W, G)) > > Martin > > > I use this initially also for G=trivial (basically I am trying to > incrementally build the stabilizer of something by iterating over the > cosets of a stabilizing group already found) so constructing a list of > which only a small part will be consumed is a bit inconvenient. However > your issue suggests to use > > for i in range(0, len(R)): > w = W(R[i]) > > This seems to work perfectly! > > I must say that I am mildly surprised that this works. I was guessing that > the coset representatives would be found on the fly in some way. > > In any case: thanks for investigating and filing the issue! > > Best, > Michel > > > On Thursday, 5 February 2026 at 11:16:52 UTC+1 Martin R wrote: > > That's a huge example. > > sage: len(libgap.RightTransversal(W, G)) > 138240 > > I think it is a gap bug, I am checking right now. > > > On Thursday, 5 February 2026 at 07:46:47 UTC+1 wrote: > > > This is very strange code - you are attempting to change the variable of > a loop inside a loop. > > > > What do you mean to do here? > > > > Dima > > Well that's not the point. Writing v=W(w) gives the same bug... > > Best, > Michel > > PS. This was just some quick test code, but this being said, I think > assigning to a loop variable is fine. This does not influence the state of > the iterator. A quick test confirms this. > > > > > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/sage-support/d6b3d5f3-7a00-4efc-a5b4-5d7f341c20ean%40googlegroups.com.
