On Regular Paths with Counting and Data Tests
Author(s) -
Everardo Bárcenas,
Edgard Benítez–Guerrero,
Jesús Lavalle
Publication year - 2016
Publication title -
electronic notes in theoretical computer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.242
H-Index - 60
ISSN - 1571-0661
DOI - 10.1016/j.entcs.2016.11.002
Subject(s) - xpath , mathematics , path expression , computer science , decidability , exptime , negation , extension (predicate logic) , theoretical computer science , path (computing) , query language , discrete mathematics , xml , algorithm , programming language , computational complexity theory , database , pspace , xml validation , operating system
Regular path expressions represent the navigation core of the XPath query language for semi-structured data (XML), and it has been characterized as the First Order Logic with Two Variables (FO2). Data tests refers to (dis)equality comparisons on data tree models, which are unranked trees with two kinds of labels, propositions from a finite alphabet, and data values from a possibly infinite alphabet. Node occurrences on tree models can be constrained by counting/arithmetic constructors. In this paper, we identify an EXPTIME extension of regular paths with data tests and counting operators. This extension is characterized in terms of a closed under negation Presburger tree logic. As a consequence, the EXPTIME bound also applies for standard query reasoning (emptiness, containment and equivalence).
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom