feat: composition lemmas about mvfderiv and mvfderivWithin

[scholzhannah]

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[github-actions]

PR summary c62909cdd1

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff (regex)

+ mvfderivWithin_comp
+ mvfderivWithin_comp_of_eq
+ mvfderivWithin_comp_of_preimage_mem_nhdsWithin
+ mvfderivWithin_comp_of_preimage_mem_nhdsWithin_of_eq
+ mvfderiv_comp
+ mvfderiv_comp_apply
+ mvfderiv_comp_apply_of_eq
+ mvfderiv_comp_mfderivWithin
+ mvfderiv_comp_mfderivWithin_of_eq
+ mvfderiv_comp_of_eq

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 c62909c).

• +10 new declarations
• −0 removed declarations

+mvfderivWithin_comp
+mvfderivWithin_comp_of_eq
+mvfderivWithin_comp_of_preimage_mem_nhdsWithin
+mvfderivWithin_comp_of_preimage_mem_nhdsWithin_of_eq
+mvfderiv_comp
+mvfderiv_comp_apply
+mvfderiv_comp_apply_of_eq
+mvfderiv_comp_mfderivWithin
+mvfderiv_comp_mfderivWithin_of_eq
+mvfderiv_comp_of_eq

---

No changes to strong technical debt.

No changes to weak technical debt.

Current commit c62909cdd1
Reference commit 20a3b032e0

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).