feat(CategoryTheory/Galois): full subcategories

[joelriou]

---

[github-actions]

PR summary 192c4c5a65

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.CategoryTheory.Galois.FullSubcategory (new file)	1025

---

Declarations diff (regex)

+ IsGaloisSubcategory
+ instance [GaloisCategory C] (P : ObjectProperty C) [P.IsGaloisSubcategory] :
++ instance [PreGaloisCategory C] [MonoCoprod C]

You can run this locally as follows

## from your `mathlib4` directory:
git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci

## summary with just the declaration names:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
../mathlib-ci/scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh in the mathlib-ci repository contains some details about this script.

Declarations diff (Lean)

✅ Lean-aware diff — post-build, computed from the Lean environment (commit 192c4c5).

• +14 new declarations
• −0 removed declarations

+CategoryTheory.GaloisCategory.instFullSubcategoryOfIsGaloisSubcategory
+CategoryTheory.ObjectProperty.IsGaloisSubcategory
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.casesOn
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.isClosedUnderColimitsOfShape_discrete
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.isClosedUnderColimitsOfShape_singleObj
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.isClosedUnderLimitsOfShape_discrete_pEmpty
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.isClosedUnderLimitsOfShape_walkingCospan
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.isClosedUnderSubobjects
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.mk
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.preservesEpimorphisms
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.rec
+CategoryTheory.ObjectProperty.IsGaloisSubcategory.recOn
+CategoryTheory.PreGaloisCategory.instFiberFunctorFullSubcategoryCompFintypeCatι
+CategoryTheory.PreGaloisCategory.instFullSubcategoryOfMonoCoprodOfIsGaloisSubcategory

---

No changes to strong technical debt.

Increase in weak tech debt: (relative, absolute) = (1.00, 0.00)

Current number	Change	Type (weak)
5048	1	exposed public sections

Current commit 192c4c5a65
Reference commit 1f8806b67d

This script lives in the mathlib-ci repository. To run it locally, from your mathlib4 directory:

git clone https://github.com/leanprover-community/mathlib-ci.git ../mathlib-ci
../mathlib-ci/scripts/reporting/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).