feat(AlgebraicTopology/Simplex): edges of a subcomplex

[joelriou]

---

[github-actions]

PR summary d7cf8a3640

Import changes for modified files

Dependency changes

File	Base Count	Head Count	Change
Mathlib.AlgebraicTopology.SimplicialSet.CompStruct	908	913	+5 (+0.55%)

Import changes for all files

Files	Import difference
3 files Mathlib.AlgebraicTopology.SimplicialSet.CompStruct Mathlib.AlgebraicTopology.SimplicialSet.NerveCodiscrete Mathlib.AlgebraicTopology.SimplicialSet.Nerve	5

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Declarations diff (regex)

+ toSubcomplex_simplex
++ toSubcomplex
++ toSubcomplex_edge

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 d7cf8a3).

• +5 new declarations
• −0 removed declarations

+SSet.Edge.CompStruct.toSubcomplex
+SSet.Edge.CompStruct.toSubcomplex_edge
+SSet.Edge.CompStruct.toSubcomplex_simplex
+SSet.Edge.toSubcomplex
+SSet.Edge.toSubcomplex_edge

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No changes to strong technical debt.

No changes to weak technical debt.

Current commit d7cf8a3640
Reference commit 38c06cd7f3

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).