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@joelriou joelriou commented Feb 21, 2025

It was previously shown that for a transfinite compositions of morphisms indexed by J, it was possible to extract a transfinite composition indexed by Set.Iic j for any j : J. In this PR, we do the same for Set.Ici j for any j : J. We deduce from these two results that in a Grothendieck abelian category, in a transfinite composition of monomorphisms given by a well ordered continuous functor F, any morphism of the form F.map f is a monomorphism.


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@joelriou joelriou added the t-category-theory Category theory label Feb 21, 2025
@github-actions github-actions bot added the large-import Automatically added label for PRs with a significant increase in transitive imports label Feb 21, 2025
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github-actions bot commented Feb 21, 2025

PR summary f62fe7f644

Import changes exceeding 2%

% File
+3.01% Mathlib.CategoryTheory.Limits.Shapes.Preorder.TransfiniteCompositionOfShape
+9.94% Mathlib.CategoryTheory.Limits.Shapes.Preorder.WellOrderContinuous
+2.99% Mathlib.CategoryTheory.MorphismProperty.TransfiniteComposition

Import changes for modified files

Dependency changes

File Base Count Head Count Change
Mathlib.CategoryTheory.Limits.Shapes.Preorder.WellOrderContinuous 664 730 +66 (+9.94%)
Mathlib.CategoryTheory.Limits.Shapes.Preorder.TransfiniteCompositionOfShape 732 754 +22 (+3.01%)
Mathlib.CategoryTheory.MorphismProperty.TransfiniteComposition 737 759 +22 (+2.99%)
Mathlib.CategoryTheory.Abelian.GrothendieckCategory.Monomorphisms 1040 1043 +3 (+0.29%)
Import changes for all files
Files Import difference
Mathlib.CategoryTheory.Abelian.GrothendieckCategory.Monomorphisms 3
5 files Mathlib.AlgebraicTopology.RelativeCellComplex.Basic Mathlib.CategoryTheory.SmallObject.Basic Mathlib.CategoryTheory.SmallObject.IsCardinalForSmallObjectArgument Mathlib.CategoryTheory.SmallObject.TransfiniteCompositionLifting Mathlib.Topology.CWComplex.Abstract.Basic
7
Mathlib.CategoryTheory.Limits.Preserves.Shapes.Preorder 21
3 files Mathlib.CategoryTheory.Limits.Shapes.Preorder.TransfiniteCompositionOfShape Mathlib.CategoryTheory.MorphismProperty.TransfiniteComposition Mathlib.CategoryTheory.SmallObject.TransfiniteIteration
22
Mathlib.CategoryTheory.Limits.Shapes.Preorder.WellOrderContinuous 66
Mathlib.Order.Interval.Set.Final (new file) 606

Declarations diff

+ IsWellOrderContinuous.restriction_setIci
+ Set.Ici.subtype_functor_final
+ mono_map
++ ici

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 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).

@mathlib4-dependent-issues-bot mathlib4-dependent-issues-bot added blocked-by-other-PR This PR depends on another PR (this label is automatically managed by a bot) and removed blocked-by-other-PR This PR depends on another PR (this label is automatically managed by a bot) labels Feb 21, 2025
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Thanks!
bors r+

@leanprover-community-mathlib4-bot leanprover-community-mathlib4-bot added the ready-to-merge This PR has been sent to bors. label Feb 21, 2025
mathlib-bors bot pushed a commit that referenced this pull request Feb 21, 2025
It was previously shown that for a transfinite compositions of morphisms indexed by `J`, it was possible to extract a transfinite composition indexed by `Set.Iic j` for any `j : J`. In this PR, we do the same for `Set.Ici j` for any `j : J`. We deduce from these two results that in a Grothendieck abelian category, in a transfinite composition of monomorphisms given by a well ordered continuous functor `F`, any morphism of the form `F.map f` is a monomorphism.



Co-authored-by: Joël Riou <37772949+joelriou@users.noreply.github.com>
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mathlib-bors bot commented Feb 21, 2025

Pull request successfully merged into master.

Build succeeded:

@mathlib-bors mathlib-bors bot changed the title feat(CategoryTheory): truncations of transfinite compositions [Merged by Bors] - feat(CategoryTheory): truncations of transfinite compositions Feb 21, 2025
@mathlib-bors mathlib-bors bot closed this Feb 21, 2025
@mathlib-bors mathlib-bors bot deleted the transfinite-composition-trunc branch February 21, 2025 08:37
Julian added a commit that referenced this pull request Feb 21, 2025
* origin/master: (823 commits)
  chore(Computability): fix naming of lemmas about Sum.inl, Sum.inr, Sum.casesOn (#22156)
  feat: `Fintype Ordering` (#22154)
  chore: more renamings to fit the naming convention (#22148)
  feat(CategoryTheory): any monomorphism in a Grothendieck abelian category is a transfinite composition of pushouts of monomorphisms in a small family (#22157)
  chore: rename `{Continuous., continuous_}sum_map` to `sumMap` (#22155)
  chore: remove initial space followed by `-/` (#22158)
  chore: make arg in HeightOneSpectrum.valuation explicit (#22139)
  feat(Data/List): `List.maximum` is monotone (#22091)
  chore(Combinatorics/SimpleGraph): extract WalkDecomp from Walk (#21981)
  feat: if a monoid M acts, then so does (s : S) with [SubmonoidClass S M] (#21123)
  chore: backport changes to `getElem` lemmas (#22146)
  feat(CategoryTheory): generating monomorphisms in Grothendieck abelian categories (#22150)
  feat: rename variables to fit doc (#22143)
  feat(CategoryTheory): IsDetecting.isIso_iff_of_mono (#22135)
  feat(CategoryTheory): truncations of transfinite compositions (#22149)
  chore: simplify a proof (#22134)
  feat(CategoryTheory): monomorphisms are stable under coproducts in Grothendieck abelian categories (#22133)
  feat(Order): Set.Ici.isSuccLimit_coe (#22103)
  chore(Analysis/Convex/Normed): split into smaller files (#22015)
  feat(Algebra/Algebra/Lie): max nilpotent ideal <= radical (#22140)
  refactor(LinearIndependent): refactor to use LinearIndepOn (#21886)
  chore: rename some more `Foo.sum_elim` -> `sumElim` (#22130)
  chore: rename Injective.sum_elim and friends (#22129)
  chore: fix naming oversight from #22070 (#22128)
  chore: fix spelling mistakes (#22136)
  feat(RingTheory/Ideal/Quotient): define transtition map between ring or module quotient by powers of ideal (#21900)
  fix: initialize_simps_projections print warning when projection data already exists (#20339)
  chore: rename ContMDiff.sum_{elim,map} (#22131)
  feat(CategoryTheory): characterization of injective objects in terms of lifting properties (#22104)
  chore(Lean,Tactic): un-indent some doc-strings (#22118)
  feat(Algebra/MvPolynomial): add `comp` versions of rename lemmas (#21259)
  chose: add deprecation (#22124)
  feat(CategoryTheory/Abelian/GrothendieckCategory): computing colimits in Subobject (#22123)
  feat(CategoryTheory/Subobject): hasCardinalLT_of_mono (#22122)
  feat: add `DenseRange.piMap` (#22114)
  feat(Algebra/Algebra/Lie): define the maximal nilpotent ideal of Lie algebras (#22061)
  chore(Data/Finset): don't import algebra when defining `Finset.card` (#21866)
  feat: a function on a discrete space is smooth (#22113)
  feat: commutative group objects in additive categories (#21521)
  style(Geometry/Manifold): remove superfluous indentation in doc-strings (#22117)
  chore: rename PushNeg.lean to Push.lean (#22108)
  feat: add Is{Open,Closed}Embedding.sum_elim (#22070)
  feat(RingTheory/Perfectoid): define the untilt map and generalize pretilt (#21563)
  feature(Topology/Algebra/Module/WeakBilin): Linear map from F into the topological dual of E with the weak topology (#21078)
  feat(CategoryTheory/Abelian): the exact sequence attached to a pushout square (#22110)
  chore(ChartedSpace.lean): group constructions together (#22107)
  feat(CategoryTheory/MorphismProperty): more basic API (#22099)
  chore(Data/Fintype): split `Fintype/Card.lean` (#21840)
  chore(SetTheory/Cardinal/Cofinality): make `IsStrongLimit` into a structure (#21971)
  feat(Combinatorics/SimpleGraph): Add a theorem about cliques in induced subgraphs (#20705)
  ...
Julian added a commit that referenced this pull request Feb 22, 2025
* polynomial-sequences: (558 commits)
  Correct the TODO to mention IsCancelAdd which does exist.
  Talk about strict monotonicity instead, thanks @pechersky.
  Mention the TODO on li generalization to semirings.
  One more dedent.
  Same injectivity twiddling for basis.
  nontiviality to simplify this proof, and some dedenting.
  Hopefully more correct injectivity lemmas matching the naming convention.
  Fix the empty docstring.
  Update Mathlib/Algebra/Polynomial/Sequence.lean
  Fix the variable naming.
  Apply suggestions from code review
  chore(Computability): fix naming of lemmas about Sum.inl, Sum.inr, Sum.casesOn (#22156)
  feat: `Fintype Ordering` (#22154)
  chore: more renamings to fit the naming convention (#22148)
  feat(CategoryTheory): any monomorphism in a Grothendieck abelian category is a transfinite composition of pushouts of monomorphisms in a small family (#22157)
  chore: rename `{Continuous., continuous_}sum_map` to `sumMap` (#22155)
  chore: remove initial space followed by `-/` (#22158)
  chore: make arg in HeightOneSpectrum.valuation explicit (#22139)
  feat(Data/List): `List.maximum` is monotone (#22091)
  chore(Combinatorics/SimpleGraph): extract WalkDecomp from Walk (#21981)
  feat: if a monoid M acts, then so does (s : S) with [SubmonoidClass S M] (#21123)
  chore: backport changes to `getElem` lemmas (#22146)
  feat(CategoryTheory): generating monomorphisms in Grothendieck abelian categories (#22150)
  feat: rename variables to fit doc (#22143)
  feat(CategoryTheory): IsDetecting.isIso_iff_of_mono (#22135)
  feat(CategoryTheory): truncations of transfinite compositions (#22149)
  chore: simplify a proof (#22134)
  feat(CategoryTheory): monomorphisms are stable under coproducts in Grothendieck abelian categories (#22133)
  feat(Order): Set.Ici.isSuccLimit_coe (#22103)
  chore(Analysis/Convex/Normed): split into smaller files (#22015)
  feat(Algebra/Algebra/Lie): max nilpotent ideal <= radical (#22140)
  refactor(LinearIndependent): refactor to use LinearIndepOn (#21886)
  chore: rename some more `Foo.sum_elim` -> `sumElim` (#22130)
  chore: rename Injective.sum_elim and friends (#22129)
  chore: fix naming oversight from #22070 (#22128)
  chore: fix spelling mistakes (#22136)
  feat(RingTheory/Ideal/Quotient): define transtition map between ring or module quotient by powers of ideal (#21900)
  fix: initialize_simps_projections print warning when projection data already exists (#20339)
  chore: rename ContMDiff.sum_{elim,map} (#22131)
  feat(CategoryTheory): characterization of injective objects in terms of lifting properties (#22104)
  chore(Lean,Tactic): un-indent some doc-strings (#22118)
  feat(Algebra/MvPolynomial): add `comp` versions of rename lemmas (#21259)
  chose: add deprecation (#22124)
  feat(CategoryTheory/Abelian/GrothendieckCategory): computing colimits in Subobject (#22123)
  feat(CategoryTheory/Subobject): hasCardinalLT_of_mono (#22122)
  feat: add `DenseRange.piMap` (#22114)
  feat(Algebra/Algebra/Lie): define the maximal nilpotent ideal of Lie algebras (#22061)
  chore(Data/Finset): don't import algebra when defining `Finset.card` (#21866)
  feat: a function on a discrete space is smooth (#22113)
  feat: commutative group objects in additive categories (#21521)
  ...
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