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feat(Geometry/Manifold): The Tangent Functor on MfldCat#38270

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feat(Geometry/Manifold): The Tangent Functor on MfldCat#38270
Deicyde wants to merge 11 commits intoleanprover-community:masterfrom
Deicyde:mfldCat-TangentFunctor

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@Deicyde Deicyde commented Apr 20, 2026

A simple motivating example for PR #38223. We define the tangentFunctor : MfldCat 𝕜 (n + 1) ⥤ MfldCat 𝕜 n which takes any manifold to its tangent bundle and any smooth map to its pushforward.

This is a standard construction in differential geometry. See: J. Lee, Smooth Manifolds, pg. 75


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@github-actions github-actions bot added the new-contributor This PR was made by a contributor with at most 5 merged PRs. Welcome to the community! label Apr 20, 2026
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github-actions bot commented Apr 20, 2026

PR summary caf1dee8e5

Import changes for modified files

No significant changes to the import graph

Import changes for all files
Files Import difference
Mathlib.Geometry.Manifold.Category.MfldCat.Basic (new file) 2216
Mathlib.Geometry.Manifold.Category.MfldCat.TangentFunctor (new file) 2217

Declarations diff

+ Hom
+ Hom.Simps.hom
+ Hom.equivContMDiffMap
+ Hom.hom
+ MfldCat
+ coe_of
+ coe_of_of
+ comp_app
+ const
+ const_apply
+ diffeomorphOfIso
+ ext
+ hom_comp
+ hom_ext
+ hom_id
+ hom_inv_id_apply
+ hom_ofHom
+ id_app
+ id_apply
+ inhabited
+ instance : Category (MfldCat 𝕜 n)
+ instance : CoeSort (MfldCat 𝕜 n) (Type u₂) := ⟨MfldCat.carrier⟩
+ instance : ConcreteCategory (MfldCat 𝕜 n)
+ instance : HasForget₂ (MfldCat 𝕜 n) TopCat.{u₂}
+ inv_hom_id_apply
+ isoOfDiffeomorph
+ ofHom
+ ofHom_apply
+ ofHom_comp
+ ofHom_hom
+ ofHom_id
+ ofNormedSpace
+ of_carrier
+ of_diffeomorphOfIso
+ of_isoOfDiffeomorph
+ tangentFunctor
++ coe_comp
++ coe_id

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.


No changes to technical debt.

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).

@github-actions github-actions bot added the t-differential-geometry Manifolds etc label Apr 20, 2026
@mathlib-dependent-issues mathlib-dependent-issues bot added the blocked-by-other-PR This PR depends on another PR (this label is automatically managed by a bot) label Apr 20, 2026
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