Suggestions for FixDetMatsReps

[jcommelin]

---

[github-actions]

PR summary fdc072ff9e

Import changes for modified files

Dependency changes

File	Base Count	Head Count	Change
Mathlib.LinearAlgebra.Matrix.FixedDetMatrices	1283	1284	+1 (+0.08%)

Import changes for all files

Files	Import difference
Mathlib.LinearAlgebra.Matrix.FixedDetMatrices	1

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Declarations diff

+ S_smul_four
+ T_S_rel
+ induction_on
+ reduce
+ reduceStep
+ reduce_mem_reps
+ reduce_of_not_pos
+ reduce_of_pos
+ reduce_rec
+ reduce_reduceStep
+ reps
+ repsFintype
+ reps_entries_le_m'
+ reps_zero_empty

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).

[jcommelin]

bot fix style

[jcommelin]

Here I expanded the proof quite a bit. But I think that the massive all_goals simp only is quite impenetrable. And hard to maintain if it might break at some point in the future.

I need to run now, so this bit isn't really polished. And I didn't attempt the other proof branch yet.

[MichaelStollBayreuth]

(I'm responsible for that, I guess; I tried to combine the two massive simp onlys that used to be there before, as they were fairly similar.)