Refining queries on a treebank with XSLT filters. Approaching the universal quantifier

This paper discusses the use of XSLT stylesheets as a filtering mechanism for refining the results of user queries on treebanks. The discussion is within the context of the TIGER treebank, the associated search engine and query language, but the general ideas can apply to any search engine for XML-encoded treebanks. It will be shown that important classes of linguistic phenomena can be accessed by applying relatively simple XSLT templates to the output of a query, effectively simulating the universal quantifier for a subset of the query language

Towards Universal Languages for Tractable Ontology Mediated Query Answering

An ontology language for ontology mediated query answering (OMQA-language) is universal for a family of OMQA-languages if it is the most expressive one among this family. In this paper, we focus on three families of tractable OMQA-languages, including first-order rewritable languages and languages whose data complexity of the query answering is in AC0 or PTIME. On the negative side, we prove that there is, in general, no universal language for each of these families of languages. On the positive side, we propose a novel property, the locality, to approximate the first-order rewritability, and show that there exists a language of disjunctive embedded dependencies that is universal for the family of OMQA-languages with locality. All of these results apply to OMQA with query languages such as conjunctive queries, unions of conjunctive queries and acyclic conjunctive queries.Comment: 10 pages, 1 figure, the full version of a paper accepted for AAAI 2020. Some typos have been correcte

Taming Existence in RDF Querying

We introduce the recursive, rule-based RDF query language RDFLog. RDFLog extends previous RDF query languages by arbitrary quantifier alternation: blank nodes may occur in the scope of all, some, or none of the universal variables of a rule. In addition RDFLog is aware of important RDF features such as the distinction between blank nodes, literals and URIs or the RDFS vocabulary. The semantics of RDFLog is closed (every answer is an RDF graph), but lifts RDF’s restrictions on literal and blank node occurrences for intermediary data. We show how to define a sound and complete operational semantics that can be implemented using existing logic programming techniques. Using RDFLog we classify previous approaches to RDF querying along their support for blank node construction and show equivalence between languages with full quantifier alternation and languages with only ∀∃ rules

Integrating a universal query mechanism into java

This thesis discusses design, architecture, and application of a universal query language embedded in Java. Utilizing various design patterns and Java\u27s polymorphism, the current result is a preprocessor that will convert an embedded language into compilable Java. The resulting Java utilizes a back{end developed for the queried data structure, capable of querying that structures internal data

Comparative Analysis of Five XML Query Languages

XML is becoming the most relevant new standard for data representation and exchange on the WWW. Novel languages for extracting and restructuring the XML content have been proposed, some in the tradition of database query languages (i.e. SQL, OQL), others more closely inspired by XML. No standard for XML query language has yet been decided, but the discussion is ongoing within the World Wide Web Consortium and within many academic institutions and Internet-related major companies. We present a comparison of five, representative query languages for XML, highlighting their common features and differences.Comment: TeX v3.1415, 17 pages, 6 figures, to be published in ACM Sigmod Record, March 200