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Beyond finite sets #623

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@EgbertRijke EgbertRijke commented May 15, 2023

This PR adds the following files to the library:

  • Foundation
    • Symmetric cores of binary relations
  • Graph Theory
    • The forgetful functor from directed graphs to undirected graphs
    • The forgetful functor from undirected graphs to directed graphs
    • The undirected core of a directed graph
    • Walks in finite undirected graphs
  • Group Theory
    • Powers of elements in commutative monoids
    • Rational commutative monoids
  • Trees
    • Finite undirected trees
  • Univalent combinatorics
    • The category of cyclically ordered sets
    • Morphisms of cyclic types
    • Omega-finite types
    • The reduced 1-bordism category
    • Symmetric operations
    • Unordered pairs of elements of finite types

The topic formalized in this PR were topics of discussion during the Beyond Finite Sets meeting. Results expected to be formalized in this PR are:

  • Show that the type of undirected trees with n nodes is pi-finite, and obtain the function that returns for each n the number of unlabeled trees with n nodes
  • Equip the 1-bordism category with the structure of a category.

@EgbertRijke EgbertRijke mentioned this pull request Sep 11, 2023
fredrik-bakke pushed a commit that referenced this pull request Sep 12, 2023
In this PR I pulled changes I made in the `foundation` and
`foundation-core` folders in the Beyond finite sets PR #623. The goal is
to create something mergeable without having to wait for the other
unfinished changes in #623. Let's see what monstrosity I created.
fredrik-bakke added a commit that referenced this pull request Sep 13, 2023
This small PR factors out rational commutative monoids from #623.

---------

Co-authored-by: Fredrik Bakke <fredrbak@gmail.com>
fredrik-bakke added a commit to fredrik-bakke/agda-unimath that referenced this pull request Sep 21, 2023
This small PR factors out rational commutative monoids from UniMath#623.

---------

Co-authored-by: Fredrik Bakke <fredrbak@gmail.com>
fredrik-bakke added a commit to fredrik-bakke/agda-unimath that referenced this pull request Sep 21, 2023
commit 6f8fdc1
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 23:22:39 2023 +0200

    hom-types are homs

commit d7cffc3
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 23:10:50 2023 +0200

    `is-set-hom`

commit 3a646ce
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 22:53:24 2023 +0200

    fix hom-set function categories

commit 3bfc7dd
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 22:49:08 2023 +0200

    rename hom-sets to `hom-set`

commit fd15e21
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 21:42:14 2023 +0200

    some comments

commit a95c86c
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Thu Sep 21 12:59:34 2023 +0200

    The classification of cyclic rings (UniMath#757)

    Co-authored-by: izak <gregapercic000@gmail.com>

commit df1e6e6
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 14:20:56 2023 +0200

    consistencies

commit 04cf136
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 14:14:52 2023 +0200

    add projections initial and terminal objects

commit 2ac83c1
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 12:42:50 2023 +0200

    Functors _between_ large...

commit 5577dbb
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 12:33:03 2023 +0200

    functors _between_ categories

commit 786664f
Merge: e0f6858 da7e412
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 12:26:28 2023 +0200

    Merge branch 'master' into functor-categories

commit e0f6858
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 02:08:26 2023 +0200

    pre-commit

commit 3933794
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Thu Sep 21 02:06:48 2023 +0200

    the functor category and natural isomorphisms

commit da7e412
Author: Vojtěch Štěpančík <vojtechstepancik@outlook.com>
Date:   Wed Sep 20 19:01:16 2023 +0200

    Coforks, coequalizers of types, their flattening lemma (UniMath#792)

    This PR introduces coforks of parallel maps, the dependent and
    non-dependent universal properties of coequalizers, the construction of
    coequalizers from pushouts, and the flattening lemma for coequalizers,
    asserting that sigmas commute with coequalizers.

    This development mirrors the development of cocones and pushouts.

    I also changed the statement of the flattening lemma for pushouts to one
    that sounds more natural to me - we can construct a cocone of sigma
    types from any cocone, not just a pushout; the previous definition
    required the vertex to be a pushout in those definitions. Now the
    statement is "if a cocone is a pushout, then the cocone derived from it
    is a pushout too".

commit d9a8a02
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Wed Sep 20 03:07:19 2023 +0200

    refactor isomorphisms in small (pre-)categories

commit f47cf60
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Wed Sep 20 00:54:35 2023 +0200

    `is-iso` to `is-iso-hom`

commit 7955721
Merge: d1a36f7 eda7bb2
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Wed Sep 20 00:31:31 2023 +0200

    Merge remote-tracking branch 'agda-unimath/master' into functor-categories

commit d1a36f7
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Wed Sep 20 00:29:10 2023 +0200

    preliminary extensionality of functors

commit 30bfd00
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Tue Sep 19 15:30:00 2023 +0200

    split up definition `functor-precategory-Precategory`

commit 3e22d2a
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Tue Sep 19 15:14:06 2023 +0200

    a little refactoring of natural transformations

commit a9f5f27
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Tue Sep 19 15:13:08 2023 +0200

    Use `C` instead of `P` dependent products of precategories

commit eda7bb2
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Tue Sep 19 22:01:57 2023 +0200

    Isomorphisms in large categories and large precategories (UniMath#791)

commit cdc008d
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Tue Sep 19 13:19:50 2023 +0200

    Add a dot after the sentence "Content created by..." (UniMath#790)

commit a081293
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Tue Sep 19 13:01:42 2023 +0200

    Add the universal property of identity systems to the overview tables (UniMath#789)

commit fec9c63
Merge: 65483f6 9d2c235
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Tue Sep 19 02:26:31 2023 +0200

    Merge branch 'master' into functor-categories

commit 65483f6
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Tue Sep 19 02:25:24 2023 +0200

    `comp-natural-transformation-Large-Precategory` and associated refactoring

commit 9c166ae
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Tue Sep 19 00:05:11 2023 +0200

    pre-commit

commit 08af608
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Tue Sep 19 00:00:34 2023 +0200

    prepend `map-` to `(obj/hom)-functor`

commit 43ee8e8
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Mon Sep 18 23:47:47 2023 +0200

    small fixes

commit 51ec628
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Mon Sep 18 23:21:34 2023 +0200

    misc cleanup natural transformations

commit 8e6f821
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Mon Sep 18 23:19:43 2023 +0200

    define representing arrow category

commit 9d2c235
Author: Vojtěch Štěpančík <vojtechstepancik@outlook.com>
Date:   Mon Sep 18 15:52:57 2023 +0200

    Fix website CI (UniMath#786)

commit 1bea263
Author: Vojtěch Štěpančík <vojtechstepancik@outlook.com>
Date:   Mon Sep 18 09:52:52 2023 +0200

    Always enable git metadata, fetch whole git history in pages CI (UniMath#785)

commit b1f027f
Author: Vojtěch Štěpančík <vojtechstepancik@outlook.com>
Date:   Mon Sep 18 03:25:35 2023 +0200

    Try to fix website CI (UniMath#784)

commit 6af959b
Author: Vojtěch Štěpančík <vojtechstepancik@outlook.com>
Date:   Mon Sep 18 03:01:42 2023 +0200

    Automatically extract page contributor information during web build (UniMath#770)

commit b66c539
Merge: 47f04e3 539174a
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Mon Sep 18 01:19:20 2023 +0200

    Merge branch 'UniMath:master' into functor-categories

commit 47f04e3
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Mon Sep 18 01:18:42 2023 +0200

    links functors between categories

commit 539174a
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Mon Sep 18 00:39:14 2023 +0200

    Yoneda's lemma for categories (UniMath#783)

commit 0106784
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Sun Sep 17 18:05:43 2023 +0200

    Moving file about hexagons of identifications (UniMath#782)

commit b804ea5
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Sun Sep 17 11:45:44 2023 +0200

    Update README.md (UniMath#781)

commit f7d6658
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Sun Sep 17 11:24:59 2023 +0200

    Update README.md (UniMath#780)

commit f4f4ef2
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Sun Sep 17 11:13:37 2023 +0200

    Update README.md (UniMath#779)

commit 6df85b4
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Sun Sep 17 11:08:03 2023 +0200

    Fancy title on repo page (UniMath#778)

commit 1fb5dc5
Author: maybemabeline <142519092+maybemabeline@users.noreply.github.com>
Date:   Sat Sep 16 22:32:19 2023 +0200

    Equivalence between the first sphere and the circle (UniMath#776)

    Co-authored-by: Egbert Rijke <e.m.rijke@gmail.com>

commit 1fe0803
Author: Fredrik Bakke <fredrbak@gmail.com>
Date:   Fri Sep 15 16:18:37 2023 +0200

    Define representations of monoids (UniMath#765)

commit c813a06
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Fri Sep 15 15:17:44 2023 +0200

    larger image, rounded corners (UniMath#774)

commit 0529896
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Fri Sep 15 13:23:30 2023 +0200

    update contributors (UniMath#773)

commit 5340335
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Fri Sep 15 10:58:02 2023 +0200

    update contributors, remove unused imports (UniMath#772)

commit 533cff1
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Fri Sep 15 01:08:32 2023 +0200

    Adding an art page (UniMath#771)

    Co-authored-by: Andrej Bauer <andrej.bauer@andrej.com>
    Co-authored-by: Matej Petković <Petkomat@users.noreply.github.com>

commit adf864e
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Thu Sep 14 16:44:32 2023 +0200

    Symmetric core of a relation (UniMath#754)

    In this PR we construct the symmetric core of a type valued relation and
    show that it is the right adjoint of the restriction functor from
    symmetric relations to relations. Everything we do in this PR is fully
    coherent and untruncated.

    ---------

    Co-authored-by: Fredrik Bakke <fredrbak@gmail.com>

commit 50fdf54
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Wed Sep 13 19:11:14 2023 +0200

    The one-object precategory of a monoid (UniMath#766)

commit 413a1bf
Author: Vojtěch Štěpančík <vojtechstepancik@outlook.com>
Date:   Wed Sep 13 18:35:55 2023 +0200

    Flattening lemma for pushouts (UniMath#764)

commit d826323
Author: Egbert Rijke <e.m.rijke@gmail.com>
Date:   Wed Sep 13 17:00:53 2023 +0200

    rational commutative monoids (UniMath#763)

    This small PR factors out rational commutative monoids from UniMath#623.

    ---------

    Co-authored-by: Fredrik Bakke <fredrbak@gmail.com>
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Could "ω-Finite types" as you define them here also faithfully be called "profinite types"?

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You can only call something a pro-object if it is an object of the procompletion of your category, in this case types. Pro types should have many nice properties which omega-finite types don’t have, such as being closed under retracts.

In general in Agda-unimath, we shouldn’t try to be too fancy with terminology. When we define a concept, it should be obvious that it is defined in the expected way.

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You mean the procompletion of finite types and maps of finite types, right?

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My comment was not meant as a suggestion, but merely as a question arising from curiosity.

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