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@Vtec234 Vtec234 commented Mar 19, 2025

  • Defines the UP of polynomial functors as a natural isomorphism of profunctors and concludes naturality_left/naturality_right from that. Along the way we build up an API for 'dependent profunctors' to express mappings such as (X, Y) ↦ ∑(g: X → A), Hom(g.left, Y) as Functor.Sigma of a functor expressing the second copmponent over yA which expresses the first component.

  • Imports lean4-seq for dependent rewriting with the rw! tactic.

  • Discuss how to integrate this with partial products.

  • Reorganize contents in the PR in correct modules.

@Vtec234 Vtec234 marked this pull request as draft March 19, 2025 20:21
@Vtec234 Vtec234 force-pushed the profunctor-naturality branch from 3a4818d to 9511690 Compare March 19, 2025 21:28
@Vtec234 Vtec234 marked this pull request as ready for review March 21, 2025 01:30
@Vtec234 Vtec234 changed the title [WIP] Profunctor naturality Profunctor naturality Mar 21, 2025
@[simps!]
def comp [HasPullbacks C] [HasTerminal C]
{E B D A : C} (P : UvPoly E B) (Q : UvPoly D A) : UvPoly (compDom P Q) (compCod P Q) :=
{E B D A : C} (P : UvPoly E B) (Q : UvPoly D A) : UvPoly (compDom P Q) (P @ A) :=
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compDom seems useful to have as an abbreviation that gets referred to a lot, but for the codomain I think just P @ A is ok; more definitions generally entail needing more lemmas later.

@sinhp sinhp merged commit e55c5b2 into sinhp:master Apr 1, 2025
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@Vtec234 Vtec234 deleted the profunctor-naturality branch April 1, 2025 16:54
@Vtec234 Vtec234 restored the profunctor-naturality branch April 1, 2025 16:54
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