chore: don't expose Nat.find or Nat.rfind

[vihdzp]

Both have highly bespoke definitions, and are best characterized by the predicate they satisfy.

---

• depends on: chore: fix all instances of linter.defProp #42463

[github-actions]

PR summary 8290d01268

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff (regex)

--++ wf_lbp

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 -- pending)

Computed after the build finishes.

---

Decrease in strong tech debt: (relative, absolute) = (3.31, 0.01)

Current number	Change	Type (strong)
678	-6	backward.privateInPublic
330	-2	backward.privateInPublic.warn

Decrease in weak tech debt: (relative, absolute) = (2.00, 0.00)

Current number	Change	Type (weak)
5045	-2	exposed public sections

Current commit 8290d01268
Reference commit b2418b0404

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).

[grunweg]

Thanks! Half of the PR is clearly useful, and the other half requires more careful attention from somebody who knows the file better.

[grunweg]

Let's hope we can split out the easy half, and then split the rest into separate PRs per file to get eyes on them?

[mathlib-dependent-issues]

This PR/issue depends on:

• chore: fix all instances of linter.defProp #42463
  By Dependent Issues (🤖). Happy coding!