In programming as well as in modelling, artefacts are required to comply with the rules of well-formedness given by their underlying language definition or their meta model, respectively. In many cases (e.g. the UML specification or the meta models implemented with EMF), these rules are given as Boolean typed OCL expressions, whose evaluation results indicate whether an artefact is well-formed....

We consider a model of multiple independent intruders that have no ability to share knowledge between each other. We use this model to analyze security in wireless ad-hoc networks, where each intruder has a local control in the network, i.e., he can read and send messages only to his direct neighbors. Another application is the mobile ambient calculus where several intruder processes are not ab...

We consider a model of multiple independent intruders that have no ability to share knowledge between each other. We use this model to analyze security in wireless ad-hoc networks, where each intruder has a local control in the network, i.e., he can read and send messages only to his direct neighbors. Another application is the mobile ambient calculus where several intruder processes are not ab...

We discuss three user interfaces for situations that involve vague retrieval requests: (1) BAROQUE, a browser for relational databases; (2) VAGUE, a query interpreter for relational databases that can handle neighborhood queries (formal queries with similar-to comparators); and (3) FLEX, an adaptive interface to relational databases that can service satisfactorily users with different levels of...

We propose an approach to verify UML model elements based on the transformation of the UML meta-model into B formal specifications. The UML meta-model is described as a combination of graphical notations, natural and formal languages. The semantics of UML elements is expressed by well-formedness rules in the UML metamodel. Their correctness is ensured by the proof of the B specifications. The a...

This is a study of a technique for deriving the session type of a program written in a statically typed imperative language from its control flow. We impose on our unlabelled session type syntax a well-formedness constraint based upon normalisation and explore the effects thereof. We present our inference algorithm declaratively and in a form suitable for implementation, and illustrate it with ...

Metamodels precisely define the constructs and underlying well-formedness rules for modelling languages. They are vital for tool vendors, who aim to provide support so that concrete models can be checked formally and automatically against a metamodel for conformance. This paper describes how an executable metamodel – which supports fully automated conformance checking – was developed using a mo...

A significant problem in computational language learning is that of inferring the content of well-formedness constraints from input data. In this article, we approach the constraint induction problem as the gradual adjustment of subsymbolic constraints in a connectionist network. In particular, we develop a multi-layer feed-forward network that learns the constraints that underlie restrictions ...

Euler diagrams are used for visualizing set-based information. Closed curves represent sets and the relationship between the curves correspond to relationships between sets. A notation is well-matched to meaning when its syntactic relationships are reflected in the semantic relationships being represented. Euler diagrams are said to be wellmatched to meaning because, for example, curve containm...

In this paper, parsing with dependency grammar is modeled as a constraint satisfaction problem. A restricted kind of constraints is proposed, which is simple enough to be implemented efficiently, but which is also rich enough to express a wide variety of grammatical well-formedness conditions. We give a number of examples to demonstrate how different kinds of linguistic knowledge can be encoded...