[Merged by Bors] - chore(FDeriv/Const): generalize to a TVS

[urkud]

Proofs about fderiv/fderivWithin were changed to avoid extra typeclass assumptions.

Also replace one simp only with simp, since the default simp set works here.

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• depends on: [Merged by Bors] - feat(FDeriv/Congr): generalize to TVS #34843

[urkud]

@eric-wieser Tagging you to avoid duplication of effort. I'm going to generalize Congr tomorrow.

[github-actions]

PR summary 30e22ac079

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

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

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/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).

[eric-wieser]

Thanks, I think actually the effort was already duplicated here, but that's my loss for not uploading a draft PR.

[mathlib-dependent-issues]

This PR/issue depends on:

• [Merged by Bors] - feat(FDeriv/Congr): generalize to TVS #34843
  By Dependent Issues (🤖). Happy coding!

[eric-wieser]

Just to check, this old proof doesn't work any more, even with the other PRs I just merged?

[urkud]

The old proof would need stronger typeclass assumptions. The new proof uses the fact that 0 is the junk value we use whenever it works to avoid these assumptions.

[eric-wieser]

Was this necessary or just golf? Fine either way, but let's mention in the description that some of the changes were golfs and not changes forced by the generalization.

[eric-wieser]

bors d+

Thanks!

[mathlib-bors]

✌️ urkud can now approve this pull request. To approve and merge a pull request, simply reply with bors r+. More detailed instructions are available here.

[urkud]

bors merge

[mathlib-bors]

Pull request successfully merged into master.

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