ManifoldSubset: New methods declare_subset, declare_superset

[mkoeppe]

Follow-up from #31736, which introduced declare_equal.

Depends on #31736

CC: @egourgoulhon @mjungmath

Component: manifolds

Author: Matthias Koeppe

Branch/Commit: c4acd09

Reviewer: Eric Gourgoulhon

Issue created by migration from https://trac.sagemath.org/ticket/31763

[mkoeppe]

Branch: u/mkoeppe/manifoldsubset__new_methods_declare_subset__declare_superset

[mkoeppe]

Last 10 new commits:

06aedf8	ManifoldSubset.{subset,superset}_digraph: New option quotient; use it for {subset,superset}_poset
c9fd9f7	ManifoldSubset.declare_equal: New
1e6a055	is_empty, declare_nonempty, has_defined_points: Add doc, examples
e06932b	Merge #31732
93b8aa3	ManifoldSubset.equal_subset_family: Fixup
5c7bb75	src/sage/manifolds/{family,manifold,subset,differentiable/manifold,**/*_submanifold}.py: Update authors, copyright
f244b87	ManifoldSubset.subset_digraph: Do not forget to include isolated vertices
b391831	Merge #31736
a6a7f02	ManifoldSubset.declare_{sub,super}set: New
0cc9eb8	src/sage/manifolds/differentiable/examples/real_line.py: Use declare_subset

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Commit: 0cc9eb8

[mkoeppe]

comment:3

Ready for review.

[egourgoulhon]

comment:4

In the docstring of declare_superset, the following changes should be made:

    def declare_superset(self, *subsets):
        r"""
-        Declare ``self`` to be a subset of each of the given supersets.
+        Declare ``self`` to be a superset of each of the given subsets.

        INPUT:

-        - ``supersets`` -- other subsets of the same manifold
+        - ``subsets`` -- other subsets of the same manifold

[egourgoulhon]

comment:5

In the doctests of declare_subset, the line

sage: M.declare_subset(V)

may look surprising at first glance, since it amounts to making all previously introduced subsets U1, U2 and V equal to the whole manifold M. Maybe a comment should be added about this, illustrated by

sage: M.equal_subset_family()
Set {M, U1, U2, V} of open subsets of the 2-dimensional differentiable manifold M

[sagetrac-git]

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

94edd68	ManifoldSubset.declare_superset: Fix documentation
41826b4	ManifoldSubset.declare_{sub,super}set: Expand docstring

[sagetrac-git]

Changed commit from 0cc9eb8 to 41826b4

[mkoeppe]

comment:7

Good idea, done

[egourgoulhon]

comment:8

Good to go!

[egourgoulhon]

Reviewer: Eric Gourgoulhon

[mkoeppe]

comment:9

Thanks for the review!