Complexity of Existential Positive First-Order Logic

Let Γ be a (not necessarily finite) structure with a finite relational signature. We prove that deciding whether a given existential positive sentence holds in Γ is in LOGSPACE or complete for the class CSP(Γ)NP under deterministic polynomial-time many-one reductions. Here, CSP(Γ)NP is the class of problems that can be reduced to the constraint satisfaction problem of Γ under non-deterministic polynomial-time many-one reductions. Key words: Computational Complexity, Existential Positive First-Order Logic, Constraint Satisfaction Problems

• Type: Conference
• Year: 2009
• Where: CIE
• Authors: Manuel Bodirsky, Miki Hermann, Florian Richoux
• Keywords: Applied Computing, CIE 2009, Constraint Satisfaction Problems, Existential Positive Sentence, Polynomial-time Many-one Reductions