ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Mon, 15 Jan 2018 14:57:35 +0100Obtaining the subposet of dissectors of a posethttps://ask.sagemath.org/question/40603/obtaining-the-subposet-of-dissectors-of-a-poset/ Following http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.93.1828&rep=rep1&type=pdf on page 3, the set of Dissectors Dis(P) of a poset P is defined as the subposet of P of elements x such that the order filter generated by x has a complement which is a principal order ideal.
Is there an easy way to obtain this poset via Sage and calculate its width?Sun, 14 Jan 2018 19:25:58 +0100https://ask.sagemath.org/question/40603/obtaining-the-subposet-of-dissectors-of-a-poset/Answer by FrédéricC for <p>Following <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.93.1828&rep=rep1&type=pdf">http://citeseerx.ist.psu.edu/viewdoc/...</a> on page 3, the set of Dissectors Dis(P) of a poset P is defined as the subposet of P of elements x such that the order filter generated by x has a complement which is a principal order ideal.
Is there an easy way to obtain this poset via Sage and calculate its width?</p>
https://ask.sagemath.org/question/40603/obtaining-the-subposet-of-dissectors-of-a-poset/?answer=40617#post-id-40617Maybe like that
sage: P = posets.PentagonPoset()
sage: [u for u in P if len(P.panyushev_complement([u]))==1]
[1, 3]
sage: P.subposet([u for u in P if len(P.panyushev_complement([u]))==1])
Finite poset containing 2 elementsMon, 15 Jan 2018 14:57:35 +0100https://ask.sagemath.org/question/40603/obtaining-the-subposet-of-dissectors-of-a-poset/?answer=40617#post-id-40617