Talk:Graded poset

Rewrite (PlanetMath)

Section added. —Nils von Barth (nbarth) (talk) 06:30, 26 February 2010 (UTC)[reply]

This page used to contain information from PlanetMath. However since the page in question does not make particularly much sense, I'm going do redo it entirely and remove the reference. Marc van Leeuwen (talk) 11:06, 4 March 2008 (UTC)[reply]

Done. Marc van Leeuwen (talk) 15:05, 5 March 2008 (UTC)[reply]

Polytopes need rank -1!

HI! I have made your article "safe" for Polytopes, where our posets need dimension -1. This was already stated, I just tidied it up. By the way, Abstract Polytopes include some very "nasty" objects whose posets are not lattices. I have amended the article accordingly. Regards and Seasons Greetings SteveWoolf (talk) 05:45, 17 December 2008 (UTC)[reply]

I removed "Face Lattices" from the Abstract Polytope in the examples, for the reasons given above. An abstract polytope is defined as a poset anyway. It doesn't have to be a lattice - but it does have to be graded. Personally, I would have preferred that an Abstract Polytope had been defined requiring it to be a lattice, and also atomistic, but we have to accept existing usage. The simplest non-lattice polytope is the Digon. SteveWoolf (talk) 20:16, 1 July 2010 (UTC)[reply]

Product

Is it true that the product of graded posets is also a graded poset? If so, I think it should be mentioned.Hiiiiiiiiiiiiiiiiiiiii (talk) 16:28, 29 January 2012 (UTC)[reply]

Graded/ranked poset

Unfortunately, there is no uniform nomenclature for graded and ranked posets, but it should be handled uniformly within Wikipedia, though. According to the current definition, the section "The usual case" fits better into the article about ranked posets. It should either be moved there or the definitions of graded and ranked posets should be interchanged (as for example in http://www.sciencedirect.com/science/article/pii/0012365X9400284P). --Maformatiker (talk) 10:21, 9 November 2016 (UTC)[reply]

Strange reference "See reference [2], p.722."

See reference [2], p.722. ... Where is the [2]?

Butler, Lynne M. (1994), Subgroup Lattices and Symmetric Functions = pages 1-156

Stanley, Richard (1997). Enumerative Combinatorics = last page = 324

Anderson, Ian (1987). Combinatorics of Finite Sets = last page = 250

Engel, Konrad (1997). Sperner Theory = last page = 417

Kung, Joseph P. S.; Rota, Gian-Carlo; Yan, Catherine H. (2009). Combinatorics: The Rota Way = last page = 396

Birkhoff: Lattice Theory = last page = 417

How and where I can find Brightwell's and West's definition?

Jumpow (talk) 20:20, 9 April 2017 (UTC)[reply]