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Evan Patterson

I am an interdisciplinary researcher working at the interface of...

  • Scientific and statistical modeling
  • Category theory and categorical logic
  • Software systems for the above

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From the blog

Changing the frame, part 2: Formal modeling with LLM assistance (10/23/2026)

“Spreadsheets with schemas” are explored as a case study for the thesis that formal models created with LLM assistance should adopt more constrained frames, yet allow the frame to be changed fluidly. A concrete example and a working demonstration are presented.

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Latest paper

Twisted double functors and loosely discrete opfibrations, 2026. Michael Lambert, David Jaz Myers, Evan Patterson.

We investigate notions of "loose module" or "loose copresheaf" over a double category: an action by the double category's loose morphisms. Two main models for loose copresheaves are introduced and compared, one based on twisted double functors—a new kind of double functor sending tight morphisms to loose morphisms and vice versa—and the other being loosely discrete opfibrations. We take the perspective that twisted copresheaves generalize indexed categories, putting the domain and codomain on an equal footing. Read more