chore(CategoryTheory): implicit_reducible for compositions of natural transformations

[joelriou]

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[github-actions]

PR summary 08f1f38de4

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff (regex)

No declarations were harmed in the making of this PR! 🐙

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 08f1f38).

• +0 new declarations
• −0 removed declarations

No declaration differences.

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No changes to strong technical debt.

No changes to weak technical debt.

Current commit 08f1f38de4
Reference commit daa38bd533

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).

[joelriou]

!bench

[leanprover-radar]

Benchmark results for 6a4614d against daa38bd are in. No significant results found. @joelriou

• 🟥 build//instructions: +4.7G (+0.00%)

No significant changes detected.

[robin-carlier]

Thanks!

maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by robin-carlier.

[JovanGerb]

I have a PR (#40925) that no_exposes hcomp. What should we do?

[robin-carlier]

I would say hcomp as no_expose makes sense. The important one at implicit_reducible here is definitely vcomp (so that NatTrans.comp_app can be an @[defeq])

[joelriou]

I have reverted the change about vcomp. This PR now only makes hcomp (i.e. the composition in the category of functors) implicit_reducible.

[robin-carlier]

@joelriou It’s the other way around: vcomp is the composition in the category of functors.

[joelriou]

@joelriou It’s the other way around: vcomp is the composition in the category of functors.

Thanks for spotting this! Fixed.

[JovanGerb]

Thanks! It now looks good to me