Hellooooooooo, > For example, by using the following commands I obtain all meet semi-lattices > with 4 elements > >>P4=[p for p in Posets(4) if p.is_meet_semilattice()] >>for p in P4: show(p.plot()) > > I wonder that the algorithm for doing this in Sage.
Oh. Well, in our terminoogy you are not really "enumerating meet_semilattices" but rather "testing if a poset is a meet_semilattice" :-) The good news is that you will find the references that you are looking for in the documentation: http://www.sagemath.org/doc/reference/combinat/sage/combinat/posets/hasse_diagram.html#sage.combinat.posets.hasse_diagram.HasseDiagram.meet_matrix And the source code is there: http://git.sagemath.org/sage.git/tree/src/sage/combinat/posets/hasse_diagram.py#n975 Regards, Nathann -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel. For more options, visit https://groups.google.com/d/optout.
