ASKSAGE: Sage Q&A Forum - Latest question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Sun, 29 Dec 2013 05:02:55 -0600preorders and posetshttp://ask.sagemath.org/question/10866/preorders-and-posets/I am looking for a module having to do with preorders (sets with reflexive and transitive relations, also called quasi-orders). I'd like to use a few of the poset methods on preorders, but this doesn't seem to work. That is, I get
Traceback (click to the left of this block for traceback)
...
ValueError: Hasse diagram contains cycles.
I figure that either there is a way to indirectly use the poset methods on preorders more generally, or else someone has implemented the quotient operation. (This turns a preorder (A,\leq) into a poset by taking the quotient under the equivalence relation \equiv on A by a \equiv b iff a \leq b and b \leq a.Larry MossSun, 29 Dec 2013 05:02:55 -0600http://ask.sagemath.org/question/10866/