On Core XPath with Inflationary Fixed Points
نویسندگان
چکیده
In this report, we prove the undecidability of Core XPath 1.0 (CXP) [6] extended with an Inflationary Fixed Point (IFP) operator. We prove that the satisfiability problem of this language is undecidable. In fact, the fragment of CXP+IFP containing only the self and descendant axes is already undecidable.
منابع مشابه
An Inflationary Fixed Point in XQuery
We introduce a controlled form of recursion in XQuery, inflationary fixed points, familiar in the context of relational databases. This imposes restrictions on the expressible types of recursion, but we show that inflationary fixed points nevertheless are sufficiently versatile to capture a wide range of interesting use cases, including the semantics of Regular XPath and its core transitive clo...
متن کامل6 th Workshop on Fixed Points in Computer Science FICS 2009
In this report, we prove the undecidability of Core XPath 1.0 (CXP) [6] extended with an Inflationary Fixed Point (IFP) operator. We prove that the satisfiability problem of this language is undecidable. In fact, the fragment of CXP+IFP containing only the self and descendant axes is already undecidable.
متن کاملWill Deflation Lead to Depletion? On Non-Monotone Fixed Point Inductions
We survey logical formalisms based on inflationary and deflationary fixed points, and compare them to the (more familiar) logics based on least and greatest fixed points.
متن کاملSatisfiability of Simple XPath Fragments under Fixed DTDs
The XPath satisfiability problem is to decide, for an XPath expression q and a DTD D, if there exists an XML document t valid against D such that the answer of q on t is nonempty. It is shown that the satisfiability problem is intractable for many XPath fragments. In this paper, we focus on fixed DTDs and consider the problem under fixed DTDs. We first show that, for a very restricted XPath fra...
متن کاملDefinable fixed points in modal and temporal logics : A survey
The paper presents a survey of author’s results on definable fixed points in modal, temporal, and intuitionistic propositional logics. The well-known Fixed Point Theorem considers the modalized case, but here we investigate the positive case. We give a classification of fixed point theorems, describe some classes of models with definable least fixed points of positive operators, special positiv...
متن کامل