Showing papers by "Jan A. Bergstra published in 1988"

Global renaming operators in concrete process algebra

Abstract: Renaming operators are introduced in concrete process algebra (concrete means that abstraction and silent moves are not considered) Examples of renaming operators are given: encapsulation, pre-abstraction, and localization We show that renamings enhance the defining power of concrete process algebra by using the example of a queue We give a definition of the trace set of a process, see when equality of trace sets implies equality of processes, and use trace sets to define the restriction of a process Finally, we describe processes with actions that have a side effect on a state space and show how to use this for a translation of computer programs into process algebra

Readies and failures in the algebra of communicating processes

Abstract: Readiness and failure semantics are studied in the setting of Algebra of Communicating Processes (ACP). A model of process graphs modulo readiness equivalence, respectively, failure equivalence, is constructed, and an equational axiom system is presented which is complete for this graph model. An explicit representation of the graph model is given, the failure model, whose elements are failure sets. Furthermore, a characterisation of failure equivalence is obtained as the maximal congruence which is consistent with trace semantics. By suitably restricting the communication format in ACP, this result is shown to carry over to subsets of Hoare’s Communicating Sequential Processes (CSP) and Milner’s Calculus of Communicating Systems (CCS). Also, the characterisation implies a full abstraction result for the failure model. In the above we restrict ourselves to finite processes without $\tau $-steps. At the end of the paper a comment is made on the situation for infinite processes with $\tau $-steps: notably w...

Process theory based on bisimulation semantics

Abstract: In this paper a process is viewed as a labeled graph modulo bisimulation equivalence. Three topics are covered: (i) specification of processes using finite systems of equations over the syntax of process algebra; (ii) inference systems which are complete for proving the equivalence of regular (finite state) processes; (iii) variations of the bisimulation model.

ACP with Signals

Abstract: New operators are introduced on top of ACP [BK 84] in order to incorporate stable signals in process algebra. Semantically this involves assigning labels to nodes of process graphs. The labels of nodes are called signals. In combination with the operators of BPA, a signal insertion operator allows to describe each finite tree labeled with actions and signals, provided the signals do not occur at leaves of the tree. In a merge processes can observe the signals of concurrent processes. This research was sponsored in part by ESPRIT under contract 432, METEOR.

Processen en procesexpressies

Abstract: Presents a brief introduction to a process theory suitable for the specification of parallel or distributed systems of computers and for the description of the semantics of a parallel programming language. Algebraic notation is used to explain parallel intercommunicating processes involving computers

Term rewriting systems with rule priorities

Abstract: In this paper we discuss term-rewriting systems with ru/e prioriries, which simply is a partial ordering on the rules. The procedural meaning of such an ordering then is, that the application of a rule of lower priority is allowed only if no rule of higher priority is applicable. The semantics of such a system is discussed. It turns out that the class of all hounded systems indeed has such a semantics.

ACP with signals

Abstract: New operators are introduced on top of ACP [BK 84] in order to incorporate stable signals in process algebra. Semantically this involves assigning labels to nodes of process graphs. The labels of nodes are called signals. In combination with the operators of BPA, a signal insertion operator allows to describe each finite tree labeled with actions and signals, provided the signals do not occur at leaves of the tree. In a merge processes can observe the signals of concurrent processes. This research was sponsored in part by ESPRIT under contract 432, METEOR.