feat(AlgebraicTopology/SimplicialSet): any simplicial set is the colimit of its monogenous subcomplexes

[joelriou]

From https://github.com/joelriou/topcat-model-category

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[github-actions]

PR summary 1e660877d7

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.AlgebraicTopology.SimplicialSet.NonDegenerateSimplicesColimit (new file)	901

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Declarations diff (regex)

+ coconeN
+ desc
+ fac
+ functorN
+ isColimitCoconeN
+ multicoequalizerDiagram

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 1e66087).

• +4 new declarations
• −0 removed declarations

+SSet.coconeN
+SSet.functorN
+SSet.functorN_obj
+SSet.isColimitCoconeN

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No changes to strong technical debt.

No changes to weak technical debt.

Current commit 1e660877d7
Reference commit 439e00243e

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).