#20727: LatticePoset: about complements
-------------------------------------+-------------------------------------
Reporter: jmantysalo | Owner:
Type: defect | Status: needs_review
Priority: major | Milestone: sage-7.3
Component: combinatorics | Resolution:
Keywords: | Merged in:
Authors: Jori Mäntysalo | Reviewers: Travis Scrimshaw
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/jmantysalo/hasse_complements | 2481a494167fa56b15742fd9b507559232517069
Dependencies: | Stopgaps:
-------------------------------------+-------------------------------------
Comment (by jmantysalo):
Replying to [comment:4 tscrim]:
> This is essentially a positive review, but I don't know the definition
of the complements of elements in a poset. I think it would be good to
give this.
(I guess you mean lattice and not poset, even if it is easy to extend the
definition to every bounded poset.)
It is said in `lattices.py` at function `complements()` already: Elements
`x` and `y` are complements if their meet and join are respectively the
bottom and the top element of the lattice.
In how many places should it be said? In `hasse_diagram.py`? In
`is_complemented()`, `is_relatively_complemented()`, and maybe later in
`is_sectionally_complemented()`? This is a real question, and I can see
arguments for both directions.
--
Ticket URL: <https://trac.sagemath.org/ticket/20727#comment:5>
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 https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
