On 2014-12-22, Nathann Cohen <nathann.co...@gmail.com> wrote: > HelloooooOO ! > >> I didn't hear about that problem before, but I could try to give it some >> thinking. Do you have any reference to start with? > > The wikipedia page contains some, including a pointer toward the > result of NP-Hardness: > http://en.wikipedia.org/wiki/Order_dimension > > It appears from time to time in graph theory because of Schnyder's > characterization of planar graphs: > http://en.wikipedia.org/wiki/Schnyder's_theorem > > I personally do not intend to use it for anything. Just being curious :-)
it is known that this dimension is equivalent to the chromatic number of certain hypergraph (hypergraph of incompatible pairs): http://www.ams.org/mathscinet-getitem?mr=1796000 Does Sage do colouring of hypergraphs (this is probably some dumb ILP way to formulate this)? 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. For more options, visit https://groups.google.com/d/optout.
