feat(Algebra/Group/Submonoid/Defs): add OneMemClass.coe_nonempty

[b-mehta]

The main value of this is to make simp stronger

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[github-actions]

PR summary 4fceb4697e

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

+ OneMemClass.coe_nonempty

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).

[plp127]

!radar

[leanprover-radar]

Benchmark results for 6a8a721 against 4fceb46 are in. There are significant results. @plp127

• 🟥 main exited with code 1

No significant changes detected.

[plp127]

LGTM, just fix the simpNF and unused arguments