feat(CategoryTheory): infer connectedness of comma categories from finality/initiality of the functor #19889
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Collaborator
javra
commented
Dec 11, 2024
javra
commented
PR summary be7d5c8b12
|
| File | Base Count | Head Count | Change |
|---|---|---|---|
| Mathlib.CategoryTheory.Comma.Final | 580 | 582 | +2 (+0.34%) |
Import changes for all files
| Files | Import difference |
|---|---|
Mathlib.CategoryTheory.Comma.Final |
2 |
Declarations diff
+ isConnected_comma_of_final
+ isConnected_comma_of_initial
+ isConnected_iff_isConnected_op
+ isConnected_iff_of_initial
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.
No changes to technical debt.
You can run this locally as
./scripts/technical-debt-metrics.sh pr_summary
- The
relativevalue is the weighted sum of the differences with weight given by the inverse of the current value of the statistic. - The
absolutevalue is therelativevalue divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).
TwoFX
reviewed
Dec 11, 2024
Comment on lines
118
to
125
| theorem isConnected_iff_of_final (F : C ⥤ D) [F.Final] : IsConnected C ↔ IsConnected D := by | ||
| rw [isConnected_iff_colimit_constPUnitFunctor_iso_pUnit.{max v u v₂ u₂} C, | ||
| isConnected_iff_colimit_constPUnitFunctor_iso_pUnit.{max v u v₂ u₂} D] | ||
| exact Equiv.nonempty_congr <| Iso.isoCongrLeft <| | ||
| CategoryTheory.Functor.Final.colimitIso F <| constPUnitFunctor.{max u v u₂ v₂} D | ||
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| /-- The domain of an initial functor is connected if and only if its codomain is connected. -/ | ||
| theorem isConnected_iff_of_initial (F : C ⥤ D) [F.Initial] : IsConnected C ↔ IsConnected D := by |
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The namespacing here is clearly an oversight, would you mind moving these out of the Types namespace? CategoryTheory.Functor is probably the right destination.
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We could also put those into a new file, wdyt?
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