#17888: Implement check for modular elements and if a poset is supersolvable
-------------------------------------+-------------------------------------
Reporter: tscrim | Owner: sage-combinat
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-6.6
Component: combinatorics | Resolution:
Keywords: | Merged in:
Authors: Travis Scrimshaw | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
public/combinat/supersolvable_posets-17888|
a15d38f0674b29e8209c952c5ad5d37911cdc722
Dependencies: | Stopgaps:
-------------------------------------+-------------------------------------
Comment (by tscrim):
Replying to [comment:2 chapoton]:
> Hmm. `is_supersolvable` does not seems very efficient to me. What about
something like that (not tested)
This is likely not as efficient because it checks all elements for
modularity, whereas the current implementation will short-circuit. I think
we can do this by starting at the lowest element, going up a cover
relation to another modular element, if no such element exists, backtrack.
I'll implement this tomorrow.
> Maybe you could also make sure that `is_modular` can take a single
element of the lattice as argument ?
How would you handle the following poset: `x ,- [x] <- [[x]]`? By
enforcing that it is always a list (or quacks like one), then there's no
ambiguity.
--
Ticket URL: <http://trac.sagemath.org/ticket/17888#comment:4>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
