# Sémin'Ouvert : « Minimal Distance of Propositional Models » par Miki Hermann (équipe AlCo)

**Speaker:**Miki Hermann

**Location:**Salle G. Kahn

**Date:**Jeu. 17 mai. 2018, 14h30-15h30

We investigate the complexity of three optimization problems in Boolean propositional logic related to information theory: Given a conjunctive formula over a set of relations, find a satisfying assignment with minimal Hamming distance to a given assignment that satisfies the formula (Next Solution) or that does not need to satisfy it (Nearest Solution). The third problem asks for two satisfying assignments with a minimal Hamming distance among all such assignments (Min Solution Distance).

For all three problems we give complete classifications with respect to the relations admitted in the formula. We give polynomial time algorithms for several classes of constraint languages. For all other cases we prove hardness or completeness regarding APX, polyAPX, or equivalence to well-known hard optimization problems.

This is joint work with Mike Behrisch (TU Wien), Stefan Mengel (CRIL), et Gernot Salzer (TU Wien).