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[Merged by Bors] - feat(LinearAlgebra/ExteriorPower): the universal property of the exterior power#18590

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[Merged by Bors] - feat(LinearAlgebra/ExteriorPower): the universal property of the exterior power#18590
joelriou wants to merge 11 commits intomasterfrom
linear-algebra-exterior-power-basic

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@joelriou joelriou commented Nov 3, 2024

We obtain the universal property of the nth exterior power of a module M: linear maps from this exterior power identify to n-alternating maps from M. This is also phrased as the data of a presentation of the exterior power by generators and relations.

Co-authored-by: sophie.morel@ens-lyon.fr


This is partly extracted from #10654, with some modifications. Mostly, what was named liftAlternatingEquiv is alternatingMapLinearEquiv here.

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@joelriou joelriou added WIP Work in progress t-algebra Algebra (groups, rings, fields, etc) labels Nov 3, 2024
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github-actions bot commented Nov 3, 2024

PR summary 604d5be7a8

Import changes for modified files

No significant changes to the import graph

Import changes for all files
Files Import difference
Mathlib.LinearAlgebra.ExteriorPower.Basic (new file) 1414

Declarations diff

+ Rels
+ alternatingMapLinearEquiv
+ alternatingMapLinearEquiv_apply_ιMulti
+ alternatingMapLinearEquiv_comp
+ alternatingMapLinearEquiv_comp_ιMulti
+ alternatingMapLinearEquiv_symm_apply
+ alternatingMapLinearEquiv_ιMulti
+ isPresentationCore
+ linearMap_eq_iff_of_eq_span
+ linearMap_eq_iff_of_span_eq_top
+ linearMap_eq_zero_iff_of_eq_span
+ linearMap_eq_zero_iff_of_span_eq_top
+ linearMap_ext
+ presentation
+ relations
+ relationsSolutionEquiv
+ ιMulti
+ ιMulti_apply_coe
+ ιMulti_span
+ ιMulti_span_fixedDegree

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.


Increase in tech debt: (relative, absolute) = (3.00, 0.00)
Current number Change Type
1525 3 erw

Current commit 604d5be7a8
Reference commit 2f1fb1baba

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).

@leanprover-community-bot-assistant leanprover-community-bot-assistant added the merge-conflict The PR has a merge conflict with master, and needs manual merging. (this label is managed by a bot) label Nov 15, 2024
@leanprover-community-bot-assistant leanprover-community-bot-assistant removed the merge-conflict The PR has a merge conflict with master, and needs manual merging. (this label is managed by a bot) label Nov 15, 2024
@jcommelin jcommelin assigned jcommelin and unassigned eric-wieser Nov 28, 2024
@jcommelin jcommelin added the awaiting-author A reviewer has asked the author a question or requested changes. label Nov 29, 2024
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Apart from the stylistic issue pointed out by Eric, I think this all looks very reasonable. But I would be happy to hear more thoughts from Eric.

@joelriou joelriou removed the awaiting-author A reviewer has asked the author a question or requested changes. label Dec 3, 2024
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bors d+

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mathlib-bors bot commented Dec 3, 2024

✌️ joelriou can now approve this pull request. To approve and merge a pull request, simply reply with bors r+. More detailed instructions are available here.

@ghost ghost added the delegated This pull request has been delegated to the PR author (or occasionally another non-maintainer). label Dec 3, 2024

variable {N : Type*} [AddCommMonoid N] [Module R N]

lemma linearMap_eq_iff_of_eq_span {V : Submodule R M} (f g : V →ₗ[R] N)
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Should this be called LinearMap.submodule_ext_iff_of_eq_span or something?

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I do not think so.

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@alreadydone alreadydone Dec 5, 2024

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Should this be called LinearMap.submodule_ext_iff_of_eq_span or something?

I like this name too. It enables dot notation, and by covnention the iff version of extensionality lemmas are usually called ext_iff, e.g. MvPolynomial.funext_iff, DFunLike.ext_iff.

Co-authored-by: Johan Commelin <johan@commelin.net>
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joelriou commented Dec 4, 2024

Thanks!

bors merge

@ghost ghost added the ready-to-merge This PR has been sent to bors. label Dec 4, 2024
mathlib-bors bot pushed a commit that referenced this pull request Dec 4, 2024
…rior power (#18590)

We obtain the universal property of the `n`th exterior power of a module `M`: linear maps from this exterior power identify to `n`-alternating maps from `M`. This is also phrased as the data of a presentation of the exterior power by generators and relations.


Co-authored-by: sophie.morel@ens-lyon.fr



Co-authored-by: Joël Riou <37772949+joelriou@users.noreply.github.com>
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mathlib-bors bot commented Dec 4, 2024

Pull request successfully merged into master.

Build succeeded:

@mathlib-bors mathlib-bors bot changed the title feat(LinearAlgebra/ExteriorPower): the universal property of the exterior power [Merged by Bors] - feat(LinearAlgebra/ExteriorPower): the universal property of the exterior power Dec 4, 2024
@mathlib-bors mathlib-bors bot closed this Dec 4, 2024
@mathlib-bors mathlib-bors bot deleted the linear-algebra-exterior-power-basic branch December 4, 2024 20:12
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5 participants