Abstract. We study sequential programs that are instruction sequences with direct and indirect jump instructions. The intuition is that indirect jump instructions are jump instructions where the position of the instruction to jump to is the content of some memory cell. We consider several kinds of indirect jump instructions. For each kind, we define the meaning of programs with indirect jump instructions of that kind by means of a translation into programs without indirect jump instructions. For each kind, the intended behaviour of a program with indirect jump instructions of that kind under execution is the behaviour of the translated program under execution on interaction with some memory device.

Secure cooperation is the problem of protecting mutually suspicious code units within the same execution environment from their potentially malicious peers. A statically enforceable capability type system is proposed for the JVM bytecode language to provide fine-grained access control of shared resources among peer code units. The design of the type system is inspired by recent advances in alias control type systems for object-oriented programming languages. The exercise of access rights and the propagation of capabilities are given a uniform interpretation as alias creation events. Each capability type assigns to a reference a dataflow trajectory, prescribing the set of aliases that is allowed to be created from the reference. An orthogonal and complementary type system for controlling object creation and downcasting is also designed to avoid a class of capability spoofing attacks. The combined type system successfully addresses a number of classical protection problems recast in a programming language context. This work therefore demonstrates the need and the feasibility of a languagebased approach to enforce application-level security among peer code units.

Analytic execution architectures have been proposed by the same authors as a means to conceptualize the cooperation between heterogeneous collectives of components such as programs, threads, states and services. Interface groups have been proposed as a means to formalize interface information concerning analytic execution architectures. These concepts are adapted to organization architectures with a focus on financial transfers. Interface groups (and monoids) now provide a technique to combine interface elements into interfaces with the flexibility to distinguish between directions of flow dependent on entity naming. The main principle exploiting interface groups is that when composing a closed system of a collection of interacting components, the sum of their interfaces must vanish in the interface group modulo reflection. This certainly matters for financial transfer interfaces. As an example of this, we specify an interface group and within it some specific interfaces concerning the financial transfer architecture for a part of our local academic organization. Financial transfer interface groups arise as a special case of more general service architecture interfaces.

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Abstract. We study sequential programs that are instruction sequences with dynamically instantiated instructions. We define the meaning of such programs in two different ways. In either case, we give a translation by which each program with dynamically instantiated instructions is turned into a program without them that exhibits on execution the same behaviour by interaction with some service. The complexity of the translations differ considerably, whereas the services concerned are equally simple. However, the service concerned in the case of the simpler translation is far more powerful than the service concerned in the other case.

A compact open file format for labeled transition systems, which are commonly used in specification and verification of concurrent systems, is introduced. This combination of openness, both in specification and implementation, and compactness is unprecedented, since existing formats in this field are either not compact, yielding files too large to be easily handled, or proprietary, hampering the development of e#cient tools.

Over the last decade formal methods have been extended towards performance and reliability evaluation. This paper tries to provide a rather intuitive explanation of the basic concepts and features in this area. The intention is to give an illustrative introduction to the basics of stochastic models, to stochastic modelling using process algebra, and to model checking as a technique to analyse stochastic models. 1 Introduction Modern industrial systems, such as communication networks, transport systems, or manufacturing systems, are more and more operating in a stochastic context: communication lines can break, bu#ers can overflow, a lorry with material for a just-in-time production line might get stuck in a tra#c jam. Each of these phenomena is stochastic by nature, its absence or presence can only be predicted up to some probability. Since these stochastic phenomena have impact on the system under consideration, it is nowadays commonly agreed that the systems themselves exhibit ...

Bernd Brael , Michael Hanus , and Frank Steiner RWTH Aachen, Germany brassel@halifax.rwth-aachen.de Institut fur Informatik, CAU Kiel, D-24098 Kiel, Germany fmh,fstg@informatik.uni-kiel.de Abstract. While declarative programming languages are based on the idea of specifying the static relationships of problems, the right modeling of the dynamic behavior is equally important for many practical applications.

In this paper we present a framework to program autonomous robots in the declarative multi-paradigm language Curry. This is an experiment to use high-level declarative programming languages for the programming of embedded systems. Our programming model is based on a recent proposal to integrate a process-oriented specification language in Curry. We show the basic ideas of our framework and demonstrate its application to robot programming.

Full formal descriptions of algorithms making use of quantum principles must take into account both quantum and classical computing components and assemble them so that they communicate and cooperate. Moreover, to model concurrent and distributed quantum computations, as well as quantum communication protocols, quantum to quantum communications which move qubits physically from one place to another must also be taken into account. Inspired by classical process algebras, which provide a framework for modeling cooperating computations, a process algebraic notation is defined, which provides a homogeneous style to formal descriptions of concurrent and distributed computations comprising both quantum and classical parts. Based upon an operational semantics which makes sure that quantum objects, operations and communications operate according to the postulates of quantum mechanics, a probabilistic branching bisimulation is defined among processes considered as having the same behavior. 1