Reference. Contextads as Wreaths; Kleisli, Para, and Span Constructions as Wreath Products

We introduce contextads and the Ctx construction, unifying various structures and constructions in category theory dealing with context and contextful arrows – comonads and their Kleisli construction, actegories and their Para construction, adequate triples and their Span construction. Contextads are defined in terms of Lack–Street wreaths, suitably categorified for pseudomonads in a tricategory of spans in a 2-category with display maps. The associated wreath product provides the Ctx construction, and by its universal property we conclude trifunctoriality. This abstract approach lets us work up to structure, and thus swiftly prove that, under very mild assumptions, a contextad equipped colaxly with a 2-algebraic structure produces a similarly structured double category of contextful arrows. We also explore the role contextads might play qua dependently graded comonads in organizing contextful computation in functional programming. We show that many side-effects monads can be dually captured by dependently graded comonads, and gesture towards a general result on the ‘transposability’ of parametric right adjoint monads to dependently graded comonads.

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Cite as @capucci-2024-contextads (helia, typst) · \cite{capucci-2024-contextads} (LaTeX)
BibTeX
bibtex · 10 lines
@misc{capucci-2024-contextads,
  doi = {10.48550/ARXIV.2410.21889},
  url = {https://arxiv.org/abs/2410.21889},
  author = {Capucci, Matteo and Myers, David Jaz},
  keywords = {Category Theory (math.CT), Programming Languages (cs.PL), FOS: Mathematics, FOS: Mathematics, FOS: Computer and information sciences, FOS: Computer and information sciences, 18D99 (Primary), 68N18 (Secondary)},
  title = {Contextads as Wreaths; Kleisli, Para, and Span Constructions as Wreath Products},
  publisher = {arXiv},
  year = {2024},
  copyright = {Creative Commons Attribution Share Alike 4.0 International}
}
hayagriva YAML (typst)
yaml · 11 lines
capucci-2024-contextads:
  type: misc
  title: Contextads as Wreaths; Kleisli, Para, and Span Constructions as Wreath Products
  author:
  - Capucci, Matteo
  - Myers, David Jaz
  date: 2024
  publisher: arXiv
  url: https://arxiv.org/abs/2410.21889
  serial-number:
    doi: 10.48550/ARXIV.2410.21889
Cites 70 works (9 here)
With notes (9)

Organizing Physics with Open Energy-Driven Systems capucci-2025-organizing

DOI · arXiv

Profunctor Optics, a Categorical Update clarke-2024-profunctor

Optics are bidirectional data accessors that capture data transformation patterns such as accessing subfields or iterating over containers. Profunctor optics are a particular choice of representation supporting modularity, meaning that we can construct accessors for complex structures by combining simpler ones. Profunctor optics have previously been studied only in an unenriched and non-mixed setting, in which both directions of access are modelled in the same category. However, functional programming languages are arguably better described by enriched categories; and we have found that some structures in the literature are actually mixed optics, with access directions modelled in different categories. Our work generalizes a classic result by Pastro and Street on Tambara theory and uses it to describe mixed V-enriched profunctor optics and to endow them with V-category structure. We provide some original families of optics and derivations, including an elementary one for traversals. Finally, we discuss a Haskell implementation.
DOI · arXiv

Diegetic Representation of Feedback in Open Games capucci-2023-diegetic

DOI · arXiv

Towards Foundations of Categorical Cybernetics capucci-2022-towards

DOI · arXiv

Translating Extensive Form Games to Open Games with Agency capucci-2022-translating

DOI · arXiv

Monoidal Grothendieck construction moeller_vasilakopoulou_2020

We lift the standard equivalence between fibrations and indexed categories to an equivalence between monoidal fibrations and monoidal indexed categories, namely lax monoidal pseudofunctors to the 2-category of categories. Furthermore, we investigate the relation between this ‘global’ monoidal version where the total category is monoidal and the fibration strictly preserves the structure, and a ‘fibrewise’ one where the fibres are monoidal and the reindexing functors strongly preserve the structure, first hinted by Shulman. In particular, when the domain is cocartesian monoidal, we show how lax monoidal structures on a pseudofunctor to Cat bijectively correspond to lifts of the pseudofunctor to MonCat. Finally, we give some examples where this correspondence appears, spanning from the fundamental and family fibrations to network models and systems.
Web · arXiv

Categorical Logic and Type Theory jacobs-1999

This book is an attempt to give a systematic presentation of both logic and type theory from a categorical perspective, using the unifying concept of fibred category. Its intended audience consists of logicians, type theorists, category theorists and (theoretical) computer scientists.

Two-dimensional monad theory blackwell_kelly_power_1989

Web

Categories for the Working Mathematician maclane_1971

Web
External (61)
capucci-2024-contextads reference entries/refs/capucci-2024-contextads/capucci-2024-contextads.hel