feat(CategoryTheory): the opposite of a triangulated category is triangulated

[joelriou]

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[github-actions]

PR summary 88aaf58be6

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference
Mathlib.CategoryTheory.Triangulated.Opposite.Triangulated (new file)	967

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Declarations diff

+ opShiftFunctorEquivalenceSymmHomEquiv
+ opShiftFunctorEquivalenceSymmHomEquiv_apply
+ opShiftFunctorEquivalenceSymmHomEquiv_left_inv
+ shiftFunctorComm_hom_app_of_add_eq_zero
+ shiftFunctorComm_inv_app_of_add_eq_zero
+ shiftFunctorCompIsoId_op_hom_app
+ shiftFunctorCompIsoId_op_inv_app
+ shift_distinguished_iff
+ shift_opShiftFunctorEquivalenceSymmHomEquiv_unop
+ shift_opShiftFunctorEquivalence_counitIso_inv_app

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).