Year: 2025
Type: article
Abstract: We extend the recently introduced setting of coherent differentiation by taking into account not only differentiation but also Taylor expansion in categories which are not necessarily (left) additive. The main idea consists in extending summability into an infinitary functor which intuitively maps any object to the object of its countable summable families. This functor is endowed with a canonical structure of a bimonad. In a linear logical categorical setting, Taylor expansion is then axiomatized as a distributive law between this summability functor and the resource comonad (aka. exponential). This distributive law allows to extend the summability functor into a bimonad on the coKleisli category of the resource comonad: this extended functor computes the Taylor expansion of the (nonlinear) morphisms of the coKleisli category. We also show how this categorical axiomatization of Taylor expansion can be generalized to arbitrary cartesian categories, leading to a general theory of Taylor expansion formally similar to that of cartesian differential categories, although it does not require the underlying cartesian category to be left additive. We provide several examples of concrete categories that arise in denotational semantics and feature such analytic structures.
Authors: Thomas Ehrhard, Aymeric Walch
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
Funder: Agence Nationale de la Recherche
OpenAlex ID: W4409373752