Sequence-based specification is a constructive method designed to convert ordinary functional requirements (that are often imprecisely and informally composed) into precise specifications. The method prompts a human requirements analyst to make the many decisions necessary to resolve the ambiguities, omissions, inconsistencies, and errors inherent in the original requirements document, and cons...

We consider the problem of rewriting semistructured queries using semistructured views. Given a client semistructured positive non-recursive query and a set of semistructured views, the algorithm nds a rewriting query that is equivalent to the client query and accesses only the views. Our solution is based on appropriately generalizing well understood techniques such as containment mappings and...

Term rewriting system is a helpful tool for implementing functional programming languages. We focus upon a transformation of term rewriting systems called currying. Currying transforms a term rewriting system with symbols of arbitrary arity into another one, which contains only nullary symbols with a single binary symbol called application. Currying in single-sorted case is explored in [1] but ...

A property P of term rewriting systems is persistent if for any many-sorted term rewriting system R, R has the property P if and only if its underlying term rewriting system Θ(R), which results from R by omitting its sort information, has the property P . It is shown that termination is a persistent property of many-sorted term rewriting systems that contain only variables of the same sort.

The relationship between Term Graph Rewriting and Term Rewriting is well understood: a single term graph reduction may correspond to several term reductions, due to sharing. It is also known that if term graphs are allowed to contain cycles, then one term graph reduction may correspond to infinitely many term reductions. We stress that this fact can be interpreted in two ways. According to the ...

A property is persistent if for any many-sorted term rewriting system , has the property if and only if term rewriting system , which results from by omitting its sort information, has the property . In this paper, we show that weak normalization is persistent for term rewriting systems. Furthermore we obtain that semi-completeness is persistent for term rewriting systems and we give the exampl...

A property is called persistent if for any manysorted term rewriting system , has the property if and only if term rewriting system , which results from by omitting its sort information, has the property . In this paper, we show that termination is persistent for non-overlapping term rewriting systems and we give the example as application of this result. Furthermore we obtain that completeness...

We present two new transformation techniques for proving termination of context-sensitive rewriting. Our rst method is simple, sound, and more powerful than previously suggested transformations. However, it is not complete, i.e., there are terminating context-sensitive rewrite systems that are transformed into non-terminating term rewrite systems. The second method that we present in this paper...

We address the issue of Ontology-Based Data Access, with ontologies represented in the framework of existential rules, also known as Datalog+/-. A well-known approach involves rewriting the query using ontological knowledge. We focus here on the basic rewriting technique which consists of rewriting a conjunctive query (CQ) into a union of CQs. We assume that the set of rules is a finite unifica...