On 2013-03-22, Nathann Cohen <nathann.co...@gmail.com> wrote: > --f46d040f9ba41d2f1404d88653eb > Content-Type: text/plain; charset=ISO-8859-1 > >> Do you mean to say that we check that (1,2) is in the domain, and >> utilize this info? > > O_O > > Are you doing this on purpose ? > > If you want to find the "orbit" of ((1,2),(1,2)) with Sage and if we > implement this "action" thing, then : > > - When you write g.action( ((1,2),(1,2)), action="OnPoints") Sage refuses > what you give it for ((1,2),(1,2)) does not belong to the domain > - When you write g.action( ((1,2),(1,2)), action="OnTuples") then Sage > checks that (1,2) is indeed in the doman (it is a vertex of your circuit) > and returns [((1,2),(1,2)), (1,1), (2,2)], that is a set of pairs (vertex, > vertex) > - When you write g.action( ((1,2),(1,2)), action="OnSets") Then Sage either > refuses to work because your "set" contains twice the same element, or > reduces your "set" to ((1,2)) in which case it returns a list of sets equal > to [((1,2)), (1), (2)] > > When is it ambiguous ?
In more detail: one writes a function that can do GAP's OnTuplesTuples action, without even any action guessing involved (this is trivial code, right, we have things like this on our ticket?), and asks it to do the orbit of the tuple of tuples ((1,2),(1,2)). The outcome --- the stuff is terribly broken --- is explained in my previous message. In particular, the "nicest" case --- infinite orbit --- is where by ((1,2),(1,2)) the caller gets his wish, to compute the orbit on the tuple of tuples of vertices of his graph, granted. Of course I assume that the function cannot read the mind of the caller as it goes to work, so it has to make a consistent choice that (1,2) is not a domain element... Just as one can derive anything from a False statement, one can always get into trouble with design that creates counterexamples to foundations of group theory. Dima > > Nathann > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
