---
title: "Politeness for the Theory of Algebraic Datatypes (Extended Abstract)"
authors:
  - "Ying Sheng"
  - "Yoni Zohar"
  - "Christophe Ringeissen"
  - "Jane Lange"
  - "Pascal Fontaine"
  - "Clark Barrett"
doi: "10.24963/ijcai.2021/660"
url: "https://ijcai.org/proceedings/2021/660"
pdf: "https://ijcai.org/proceedings/2021/0660.pdf"
venue: "Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence"
year: 2021
pages: "4829-4833"
track: "Sister Conferences Best Papers"
keywords:
  - "Constraints and SAT: Constraint Satisfaction"
  - "Constraints and SAT: SAT: Algorithms and Techniques"
  - "Constraints and SAT: Satisfiability Modulo Theories"
  - "Constraints and SAT: Constraints: Modeling, Solvers, Applications"
---

# Politeness for the Theory of Algebraic Datatypes (Extended Abstract)

Ying Sheng, Yoni Zohar, Christophe Ringeissen, Jane Lange, Pascal Fontaine, Clark Barrett

*Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence*, pages 4829-4833. DOI: [10.24963/ijcai.2021/660](https://doi.org/10.24963/ijcai.2021/660)

## Abstract

Algebraic datatypes, and among them lists and trees, have attracted a lot of interest in automated reasoning and Satisfiability Modulo Theories (SMT). Since its latest stable version, the SMT-LIB standard defines a theory of algebraic datatypes, which is currently supported by several mainstream SMT solvers. In this paper, we study this particular theory of datatypes and prove that it is strongly polite, showing also how it can be combined with other arbitrary disjoint theories using polite combination. Our results cover both inductive and finite datatypes, as well as their union. The combination method uses a new, simple, and natural notion of additivity, that enables deducing strong politeness from (weak) politeness.