Filtering Isomorphic Models by Invariants (Short Paper)

Authors João Araújo , Choiwah Chow , Mikoláš Janota

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Author Details

João Araújo
  • NOVA University Lisbon, Portugal
Choiwah Chow
  • Universidade Aberta, Lisbon, Portugal
Mikoláš Janota
  • Czech Technical University in Prague, Czech Republic

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João Araújo, Choiwah Chow, and Mikoláš Janota. Filtering Isomorphic Models by Invariants (Short Paper). In 27th International Conference on Principles and Practice of Constraint Programming (CP 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 210, pp. 4:1-4:9, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)


The enumeration of finite models of first order logic formulas is an indispensable tool in computational algebra. The task is hindered by the existence of isomorphic models, which are of no use to mathematicians and therefore are typically filtered out a posteriori. This paper proposes a divide-and-conquer approach to speed up and parallelize this process. We design a series of invariant properties that enable us to partition existing models into mutually non-isomorphic blocks, which are then tackled separately. The presented approach is integrated into the popular tool Mace4, where it shows tremendous speed-ups for a variety of algebraic structures.

Subject Classification

ACM Subject Classification
  • Computing methodologies
  • Theory of computation → Constraint and logic programming
  • finite model enumeration
  • isomorphism
  • invariants
  • Mace4


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