• Cauchy Completeness, Lax Epimorphisms and Effective Descent for Split Fibrations 

      [OWP-2023-06] Lucatelli Nunes, Fernando; Prezado, Rui; Sousa, Lurdes (Mathematisches Forschungsinstitut Oberwolfach, 2023-06-19)
      For any suitable base category V, we find that V-fully faithful lax epimorphisms in V-Cat are precisely those V-functors F:AB ...
    • Lax Comma Categories of Ordered Sets 

      [OWP-2023-08] Clementino, Maria Manuel; Lucatelli Nunes, Fernando (Mathematisches Forschungsinstitut Oberwolfach, 2023-06-19)
      Let Ord be the category of (pre)ordered sets. Unlike Ord/X, whose behaviour is well-known, not much can be found in the literature about the lax comma 2-category Ord//X. In this paper ...
    • Logical Relations for Partial Features and Automatic Differentiation Correctness 

      [OWP-2023-09] Lucatelli Nunes, Fernando; Vákár, Matthijs (Mathematisches Forschungsinstitut Oberwolfach, 2023-06-19)
      We present a simple technique for semantic, open logical relations arguments about languages with recursive types, which, as we show, follows from a principled foundation in categorical semantics. We demonstrate how it can ...
    • Semantic Factorization and Descent 

      [OWP-2023-05] Lucatelli Nunes, Fernando (Mathematisches Forschungsinstitut Oberwolfach, 2023-06-19)
      Let A be a 2-category with suitable opcomma objects and pushouts. We give a direct proof that, provided that the codensity monad of a morphism p exists and is preserved by a suitable morphism, the factorization ...