chore(CategoryTheory): fix diamond for the preadditive structure on the opposite category

[joelriou]

See #mathlib4 > diamond for Preadditive/HasZeroMorphisms and op

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[github-actions]

PR summary 71f5543cfd

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

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

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

Current number	Change	Type
6532	-2	backward.isDefEq.respectTransparency

Current commit 7a62c773c0
Reference commit 71f5543cfd

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).

[riccardobrasca]

Can you add the rfl proof that now works as an example?

[joelriou]

Can you add the rfl proof that now works as an example?

Thanks for the suggestion! I have just added it.

[joelriou]

!bench

[leanprover-radar]

Benchmark results for 7a62c77 against 71f5543 are in. No significant results found. @joelriou

• 🟥 build//instructions: +14.3G (+0.01%)

Small changes (2✅, 1🟥)

• ✅ build/module/Mathlib.Tactic.CasesM//instructions: -130.1M (-2.24%)
• ✅ build/module/Mathlib.Tactic.Linarith.Preprocessing//instructions: -717.0M (-4.58%)
• 🟥 build/module/Mathlib.Tactic.MinImports//instructions: +139.4M (+2.77%)