On closure operators related to maximal tricliques in tripartite hypergraphs

TL;DR

This paper introduces a valid closure operator for enumerating maximal triadic cliques in tripartite hypergraphs, addressing inconsistencies in previous operators and analyzing related complexity issues.

Contribution

It defines a proper closure operator for triconcepts and studies the associated set systems, clarifying theoretical and computational challenges.

Findings

Previous operators are inconsistent for triconcept enumeration

A new valid closure operator is proposed

Complexity classes of related problems are analyzed

Abstract

Triadic Formal Concept Analysis (3FCA) was introduced by Lehman and Wille almost two decades ago. And many researchers work in Data Mining and Formal Concept Analysis using the notions of closed sets, Galois and closure operators, closure systems, but up-to-date even though that different researchers actively work on mining triadic and n-ary relations, a proper closure operator for enumeration of triconcepts, i.e. maximal triadic cliques of tripartite hypergaphs, was not introduced. In this paper we show that the previously introduced operators for obtaining triconcepts and maximal connected and complete sets (MCCSs) are not always consistent and provide the reader with a definition of valid closure operator and associated set system. Moreover, we study the difficulties of related problems from order-theoretic and combinatorial point view as well as provide the reader with justifications of the complexity classes of these problems.