84 research outputs found
Characterizing Quantifier Extensions of Dependence Logic
We characterize the expressive power of extensions of Dependence Logic and
Independence Logic by monotone generalized quantifiers in terms of quantifier
extensions of existential second-order logic.Comment: 9 page
Computational Aspects of Logics in Team Semantics (Tutorial)
Non peer reviewe
On Independence Atoms and Keys
Uniqueness and independence are two fundamental properties of data. Their
enforcement in database systems can lead to higher quality data, faster data
service response time, better data-driven decision making and knowledge
discovery from data. The applications can be effectively unlocked by providing
efficient solutions to the underlying implication problems of keys and
independence atoms. Indeed, for the sole class of keys and the sole class of
independence atoms the associated finite and general implication problems
coincide and enjoy simple axiomatizations. However, the situation changes
drastically when keys and independence atoms are combined. We show that the
finite and the general implication problems are already different for keys and
unary independence atoms. Furthermore, we establish a finite axiomatization for
the general implication problem, and show that the finite implication problem
does not enjoy a k-ary axiomatization for any k
Decidability of predicate logics with team semantics
We study the complexity of predicate logics based on team semantics. We show
that the satisfiability problems of two-variable independence logic and
inclusion logic are both NEXPTIME-complete. Furthermore, we show that the
validity problem of two-variable dependence logic is undecidable, thereby
solving an open problem from the team semantics literature. We also briefly
analyse the complexity of the Bernays-Sch\"onfinkel-Ramsey prefix classes of
dependence logic.Comment: Extended version of a MFCS 2016 article. Changes on the earlier arXiv
version: title changed, added the result on validity of two-variable
dependence logic, restructurin
Set Semantics for Asynchronous TeamLTL: Expressivity and Complexity
We introduce and develop a set-based semantics for asynchronous TeamLTL. We consider two canonical logics in this setting: the extensions of TeamLTL by the Boolean disjunction and by the Boolean negation. We relate the new semantics with the original semantics based on multisets and establish one of the first positive complexity theoretic results in the temporal team semantics setting. In particular we show that both logics enjoy normal forms that can be utilised to obtain results related to expressivity and complexity (decidability) of the new logics
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