http://trac.sagemath.org/ticket/17485 http://trac.sagemath.org/ticket/17487
I can modify the docs and/or code if needed, but don't know for sure what to do.
-- Jori Mäntysalo
There has been some discussion about 'graded' vs. 'ranked' in posets.
However, these two tickets are still waiting someone knowing about the
area to clarify:
