feat(Analysis/Convolution): add convolution_symm, convolution, (3 more lemmas)

[lakesare]

From the Carleson project.

---

Upstreaming from Carleson: /Carleson/ToMathlib/Analysis/Convolution.lean

[github-actions]

Welcome new contributor!

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[lakesare]

carleson

[github-actions]

PR summary 2ac0316f25

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff (regex)

+ AEStronglyMeasurable.convolution
+ ConvolutionExists.of_memLp_memLp
+ convolution_symm
+ enorm_convolution_le_eLpNorm_mul_eLpNorm
+ lintegral_enorm_convolution_integrand_le_eLpNorm_mul_eLpNorm

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 2ac0316).

• +5 new declarations
• −0 removed declarations

+MeasureTheory.AEStronglyMeasurable.convolution
+MeasureTheory.ConvolutionExists.of_memLp_memLp
+MeasureTheory.convolution_symm
+MeasureTheory.enorm_convolution_le_eLpNorm_mul_eLpNorm
+MeasureTheory.lintegral_enorm_convolution_integrand_le_eLpNorm_mul_eLpNorm

---

No changes to strong technical debt.

No changes to weak technical debt.

Current commit 2ac0316f25
Reference commit 87a6eccfb8

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).

[lakesare]

WIP