#19191: LatticePoset: add is_planar()
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Reporter: jmantysalo | Owner:
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-6.9
Component: combinatorics | Resolution:
Keywords: | Merged in:
Authors: Jori Mäntysalo | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/jmantysalo/latticeposet__add_is_planar__|
c669ecbf2476518175f0719ba25e76cdc05f1521
Dependencies: | Stopgaps:
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Comment (by ncohen):
> This is about planarity of lattices, not posets in general.
The paper I sent you previously says that a *Poset* is planar if its hasse
diagram is planar.
The first paragraph (not the abstract) in the first paper that you
mentionned says that the definition is (naturally) the same for posets,
i.e. that they are planar whenever their hasse diagram is planar.
What the first paper claims in its title is that you can *chose* to add
the `(0,n-1)` edge without changing the property.
What the slideshow says in its 12th page looks contradictory with the two
papers above. If you can find the paper it quotes, perhaps that will
clarify it.
Nathann
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Ticket URL: <http://trac.sagemath.org/ticket/19191#comment:13>
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