LatticePoset: certificate for is_pseudocomplemented()

[jm58660]

Add an option to get an element without the pseudocomplement. (Compare to .is_complemented(certificate=True).

Component: combinatorics

Author: Jori Mäntysalo

Branch/Commit: 69e0b1e

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/21505

[jm58660]

Branch: u/jmantysalo/pseudocomp-certificate

[jm58660]

comment:2

Should it be "an element without the pseudocomplement" or "an element without a pseudocomplement", as an element can have at most one pseudocomplemet?

---

New commits:

4785ba6

Add certificate-option to is_pseudocomplemented().

[jm58660]

Commit: 4785ba6

[tscrim]

comment:3

I would say "a pseudocomplement" both in case one does not exist and so it makes it seem less like there is one pseudocomplement for all lattices (which you could get around by saying "the pseudocomplement of the lattice").

[sagetrac-git]

Changed commit from 4785ba6 to 1ed0863

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

1ed0863

'the' or 'a'.

[jm58660]

comment:5

Replying to @tscrim:

I would say "a pseudocomplement" - -

OK. Thanks.

[jm58660]

comment:6

Travis, can you also review this? Should be trivial.

(Not that important, but kind of nice to have unified format of is_* -functions when possbile.)

[tscrim]

Reviewer: Travis Scrimshaw

[tscrim]

comment:7

Is there a reason why you have one as 3 lines if-return and the other as a 1 line return foo if bar else True? I think it would be good to be consistent. Once addressed, you can set a positive review on my behalf.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

69e0b1e

Reformatting return-if-else.

[sagetrac-git]

Changed commit from 1ed0863 to 69e0b1e

[jm58660]

comment:9

Replying to @tscrim:

Is there a reason why you have one as 3 lines if-return and the other as a 1 line return foo if bar else True? I think it would be good to be consistent. Once addressed, you can set a positive review on my behalf.

Done that. Thanks.

[vbraun]

comment:10

sage -t --long src/sage/combinat/posets/lattices.py
**********************************************************************
File "src/sage/combinat/posets/lattices.py", line 1272, in sage.combinat.posets.lattices.FiniteLatticePoset.is_pseudocomplemented
Failed example:
    L.is_pseudocomplemented(certificate=True)
Exception raised:
    Traceback (most recent call last):
      File "/home/buildbot/slave/sage_git/build/local/lib/python2.7/site-packages/sage/doctest/forker.py", line 498, in _run
        self.compile_and_execute(example, compiler, test.globs)
      File "/home/buildbot/slave/sage_git/build/local/lib/python2.7/site-packages/sage/doctest/forker.py", line 861, in compile_and_execute
        exec(compiled, globs)
      File "<doctest sage.combinat.posets.lattices.FiniteLatticePoset.is_pseudocomplemented[4]>", line 1, in <module>
        L.is_pseudocomplemented(certificate=True)
    TypeError: is_pseudocomplemented() got an unexpected keyword argument 'certificate'
**********************************************************************
1 item had failures:
   1 of   7 in sage.combinat.posets.lattices.FiniteLatticePoset.is_pseudocomplemented
    [347 tests, 1 failure, 1.10 s]

[jm58660]

comment:11

Replying to @vbraun:

        L.is_pseudocomplemented(certificate=True)
    TypeError: is_pseudocomplemented() got an unexpected keyword argument 'certificate'

??? I can not get that error message. It seems that the code has been tested before compiling.

[tscrim]

comment:12

I agree with Jori's assessment.

[vbraun]

Changed branch from u/jmantysalo/pseudocomp-certificate to 69e0b1e