Taxonomy of XML schema languages using formal language theory

Abstract

On the basis of regular tree grammars, we present a formal framework for XML schema languages. This framework helps to describe, compare, and implement such schema languages in a rigorous manner. Our main results are as follows: (1) a simple framework to study three classes of tree languages (local, single-type, and regular); (2) classification and comparison of schema languages (DTD, W3C XML Schema, and RELAX NG) based on these classes; (3) efficient document validation algorithms for these classes; and (4) other grammatical concepts and advanced validation algorithms relevant to an XML model (e.g., binarization, derivative-based validation).

LinkEHR-Ed: A multi-reference model archetype editor based on formal semantics

“…The proposed abstraction for the data definition section of archetypes is based on labeled trees which have been extensively used for modeling XML schemas and queries [20][28][37] [38]. Archetype specialization is modeled by a subsumption relation.…”

“…PERSON[at0001], is indicated by using the same identifier, followed by an We have also developed an algorithm that takes two schemas as input and calculates the set of subsumption functions between them. It is a generalization of the algorithm described in [20] …”

Complexity of Decision Problems for Simple Regular Expressions

“…The rule for store specifies that there should be at least two DVDs on discount. The following restriction on SDTDs corresponds to the expressiveness of XML schema languages [19]. The above defined SDTD is not single type as both dvd 1 and dvd 2 occur in the rule for store.…”

“…The above defined SDTD is not single type as both dvd 1 and dvd 2 occur in the rule for store. The classes of tree languages defined by the grammars introduced above are included as follows: DTD SDTD st SDTD [3,19].…”

“…Section 2 for a detailed definition and Table 1 for a list of allowed factors together with their abbreviated notation). Further, Murata et al argued that XML Schemas do not correspond to the full class of tree automata or SDTDs, but to a strict subset of those, namely, single-type SDTDs [19].…”