[Merged by Bors] - chore(GroupTheory): deduplicate RootableBy.surjective_pow

[wwylele]

pow_left_surj_of_rootableBy and RootableBy.surjective_pow have the same statement, so this PR deprecates one of them. I kept the one with better naming (surj is not a widely used abbrev)

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[github-actions]

PR summary 700fcd702f

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

+ smul_right_surj_of_divisibleBy

You can run this locally as follows

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

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

The doc-module for scripts/pr_summary/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/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).

[wwylele]

easy

[tb65536]

Thanks!

maintainer merge

[github-actions]

🚀 Pull request has been placed on the maintainer queue by tb65536.

[riccardobrasca]

Thanks!

bors merge

[mathlib-bors]

Pull request successfully merged into master.

Build succeeded:

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