Formal properties of XML grammars and languages

We consider XML documents described by a document type definition (DTD). An XML-grammar is a formal grammar that captures the syntactic features of a DTD. We investigate properties of this family of grammars. We show that every XML-language basically has a unique XMLgrammar. We give two characterizations of languages generated by XMLgrammars, one is set-theoretic, the other is by a kind of saturation property. We investigate decidability problems and prove that some properties that are undecidable for general context-free languages become decidable for XML-languages. We also characterize those XML-grammars that generate regular XML-languages. R

• Type: Journal
• Year: 2002
• Where: ACTA
• Authors: Jean Berstel, Luc Boasson
• Keywords: ACTA 2002, Document, Nous, Une Grammaire