• March 2004. Conjecture 5.4.6, the extension of Stanley's Conjecture, is false. In other words, there exist oriented posets that are not isomorphic to cylindric skew shapes but whose generating functions are symmetric. The smallest counterexamples have 7 vertices, and are shown below. These examples were found using John Stembridge's posets package for Maple.

The thesis in pdf, ps or ps.gz.