LatticePosets: Add congruence-related functions / part 2

[jm58660]

This patch adds functions to check if the lattice is regular, uniform or isoform.

Second, "backend" functions will make it easier to construct the lattice of congruences.

Third, there was a slight error in congruence() of Hasse diagram with start-parameter. This patch corrects that.

Related: #20058, #22225, #22238, #22229.

Depends on #22225

CC: @mantepse @tscrim @fchapoton

Component: combinatorics

Author: Jori Mäntysalo

Branch/Commit: 5fc745e

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/21861

[jm58660]

Branch: u/jmantysalo/latticeposets__add_congruence_related_functions___part_2

[jm58660]

comment:3

Whole set: Needs comments about the code implementation, the code PEP-compliance, the documentation and the examples used.

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New commits:

d96afed

Add three congruence-related frontend-functions, two to backend.

[jm58660]

Commit: d96afed

[jm58660]

comment:4

If wanted, I can of course split this ticket to several separate tickets.

[jm58660]

comment:5

One doctest fails, but that is already taken care by #22225.

[sagetrac-git]

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

dd5be6c

Merge branch 'develop' into t/21861/latticeposets__add_congruence_related_functions___part_2

[sagetrac-git]

Changed commit from d96afed to dd5be6c

[tscrim]

comment:7

Can you add a test showing the bug is fixed? Also, what about the TODO comment?

[sagetrac-git]

Changed commit from dd5be6c to 699f24d

[sagetrac-git]

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

699f24d

Doctest a bug correction.

[jm58660]

comment:9

Replying to @tscrim:

Can you add a test showing the bug is fixed?

Good point. Added.

Also, what about the TODO comment?

Well, I haven't thinked yet :=). The code works, but it can be that it does unnecessary computing.

[tscrim]

comment:10

This hits the same error on the number of functions as the other ticket (sorry, I don't remember the number offhand), so that is a (soft) dependency of this ticket.

If you haven't thought about it yet and don't plan on doing so soon, then could you change the TODO comment to seem less like it is targeted to yourself? (Sorry, I don't really understand the comment, so I can't quite help here.)

[sagetrac-git]

Changed commit from 699f24d to 5fc745e

[sagetrac-git]

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

5fc745e

Removed todo-notes.

[jm58660]

Dependencies: #22225

[jm58660]

comment:12

Replying to @tscrim:

This hits the same error on the number of functions as the other ticket (sorry, I don't remember the number offhand), so that is a (soft) dependency of this ticket.

Added.

If you haven't thought about it yet and don't plan on doing so soon, then could you change the TODO comment to seem less like it is targeted to yourself?

As you wish, removed. I guess everyone looking at the code can see that there might be a place for optimization.

The question can be phrased like this: "Suppose that the congruence generated by pair (a,b) is regular, and so is the congruence generated by (c,d). Is the congruence generated by both together then also regular?" (And same for uniform and isoform congruences.)

[tscrim]

Reviewer: Travis Scrimshaw

[tscrim]

comment:13

Replying to @jm58660:

Replying to @tscrim:

If you haven't thought about it yet and don't plan on doing so soon, then could you change the TODO comment to seem less like it is targeted to yourself?

As you wish, removed. I guess everyone looking at the code can see that there might be a place for optimization.

Thanks. Positive review.

The question can be phrased like this: "Suppose that the congruence generated by pair (a,b) is regular, and so is the congruence generated by (c,d). Is the congruence generated by both together then also regular?" (And same for uniform and isoform congruences.)

Alas, I have no idea, sorry.

[jm58660]

comment:14

Thanks Travis! Not only for this one, but for several tickets.

[vbraun]

Changed branch from u/jmantysalo/latticeposets__add_congruence_related_functions___part_2 to 5fc745e