With the growing interest in modular ontology languages to address the need for collaborative development, integration, and use of ontologies on the Web, there is an urgent need fo...
We define regular expressions for unranked trees (actually, ordered sequences of unranked trees, called forests). These are compared to existing regular expressions for trees. On ...
DTDs and XML Schema are important validation languages for XML documents. They lie at opposite ends of a spectrum of validation languages in terms of expressive power and readabil...
We define the reachability-bound problem to be the problem of finding a symbolic worst-case bound on the number of times a given control location inside a procedure is visited in ...
For decades we have been using Chomsky's generative system of grammars, particularly context-free grammars (CFGs) and regular expressions (REs), to express the syntax of prog...