Opened 5 years ago
Last modified 5 weeks ago
#25763 needs_info enhancement
Posets: Add is_prime
Reported by:  jmantysalo  Owned by:  

Priority:  major  Milestone:  
Component:  combinatorics  Keywords:  
Cc:  mantepse  Merged in:  
Authors:  Jori Mäntysalo  Reviewers:  Travis Scrimshaw 
Report Upstream:  N/A  Work issues:  
Branch:  u/jmantysalo/primeposet (Commits, GitHub, GitLab)  Commit:  0dd297678c4399c0bcdfb9f9607a693143cb5edf 
Dependencies:  Stopgaps: 
Description
Add function to check if a poset is prime (or 'decomposable'), i.e. have no untrivial autonomous subset.
Change History (8)
comment:1 Changed 5 years ago by
Branch:  → u/jmantysalo/primeposet 

comment:2 Changed 5 years ago by
Cc:  mantepse added 

Commit:  → 5b36637f69e0949a2e531b95d675a967b812f4c1 
Status:  new → needs_review 
comment:3 followup: 5 Changed 5 years ago by
Reviewers:  → Travis Scrimshaw 

Two little doc things:
:meth:`~FinitePoset.is_prime`  Return ``True`` if the poset can be written as a lexicographic sum of other posets.
Shouldn't this be cannot be written
?
untrivial
> non trivial
.
Otherwise LGTM, and you can set this to a positive review on my behalf once fixed.
comment:4 Changed 5 years ago by
Commit:  5b36637f69e0949a2e531b95d675a967b812f4c1 → 0dd297678c4399c0bcdfb9f9607a693143cb5edf 

Branch pushed to git repo; I updated commit sha1. New commits:
0dd2976  Minor modifications to doc.

comment:5 Changed 5 years ago by
Status:  needs_review → positive_review 

Replying to tscrim:
Shouldn't this be
cannot be written
?
Good point. The function was is_decomposable
at first.
Marked as positive review. Thanks.
comment:6 Changed 5 years ago by
Milestone:  sage8.3 → sage8.4 

comment:7 Changed 5 years ago by
Status:  positive_review → needs_info 

Won't work reliably until #25872. I put this on hold.
comment:8 Changed 5 weeks ago by
Milestone:  sage8.4 

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Could be also
is_decomposable
, don't know if that would be better.New commits:
Add is_prime() to posets.