English

Fuzzy Algebraic Theories

Logic in Computer Science 2021-10-22 v1 Category Theory Logic

Abstract

In this work we propose a formal system for fuzzy algebraic reasoning. The sequent calculus we define is based on two kinds of propositions, capturing equality and existence of terms as members of a fuzzy set. We provide a sound semantics for this calculus and show that there is a notion of free model for any theory in this system, allowing us (with some restrictions) to recover models as Eilenberg-Moore algebras for some monad. We will also prove a completeness result: a formula is derivable from a given theory if and only if it is satisfied by all models of the theory. Finally, leveraging results by Milius and Urbat, we give HSP-like characterizations of subcategories of algebras which are categories of models of particular kinds of theories.

Keywords

Cite

@article{arxiv.2110.10970,
  title  = {Fuzzy Algebraic Theories},
  author = {Davide Castelnovo and Marino Miculan},
  journal= {arXiv preprint arXiv:2110.10970},
  year   = {2021}
}
R2 v1 2026-06-24T07:03:57.270Z