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We present ECCE and LOGEN, two partial evaluators for Prolog using the online and offline approach respectively. We briefly present the foundations of these tools and discuss various applications. We also present new implementations of these tools, carried out in Ciao Prolog. In addition to a command-line interface new user-friendly web interfaces were developed. These enable non-expert users to specialise logic programs using a web browser, without the need for a local installation.

Abstract. We describe the use of a flexible meta-interpreter for performing access control checks on deductive databases. The meta-program is implemented in Prolog and takes as input a database and an access policy specification. For processing access control requests we specialise the meta-program for a given access policy and database by using the logen partial evaluation system. The resulting specialised control checking program is dependent solely upon dynamic information that can only be known at the time of actual access request evaluation. In addition to describing our approach, we give a number of performance measures for our implementation of an access control checker. In particular, we show that by using our approach we get flexible access control with virtually no overhead, satisfying the Jones optimality criterion. The paper also shows how to satisfy the Jones optimality criterion more generally for interpreters written in the non-ground representation.

We describe the use of a flexible meta-interpreter for performing access control checks on deductive databases. The meta-program is implemented in Prolog and takes as input a database and an access policy specification. We then proceed to specialise the meta-program for a given access policy and intensional database by using the logen partial evaluation system. In addition to describing the programs involved in our approach, we give a number of performance measures for our implementation of an access control checker, and we discuss the implications of using this approach for access control on deductive databases. In particular, we show that by using our approach we get flexible access control with virtually zero overhead.

This paper addresses the interrelation between control and data flow in embedded system models through a new design representation, called Dual Flow Net (DFN). A modeling formalism with a very close-fitting control and data flow is achieved by this representation, as a consequence of enhancing its underlying Petri net structure. The work presented in this paper does not only tackle the modeling side in embedded systems design, but also the validation of embedded system models through formal methods. Various introductory examples illustrate the applicability of the DFN principles, whereas the capability of the model to with complex designs is demonstrated through the design and verification of a real-life Ethernet coprocessor.