Modelling Local Variables: Possible Worlds and Object Spaces

Worlds: Controlling the Scope of Side Effects

The state of an imperative program—e.g., the values stored in global and local variables, arrays, and objects’ instance variables—changes as its statements are executed. These changes, or side effects, are visible globally: when one part of the program modifies an object, every other part that holds a reference to the same object (either directly or indirectly) is also affected. This paper intr...

Modelling Global and Local Name Spaces for Mobile Agents Using Object Nets

Preliminary considerations on the modelling of belief change operators by metric spaces

In this paper, a possible worlds framework for representing general belief change operators is presented. In common with many approaches, an agent’s set of beliefs are specified by a subset of the set of possible worlds. The central intuition is that there is a distance given between every pair of possible worlds, giving the similarity of one world to another; the set of worlds together with th...

The Essence of Parallel Algol

We consider a parallel Algol-like language, combining procedures with shared-variable parallelism. Procedures permit encapsulation of common parallel programming idioms. Local variables provide a way to restrict interference between parallel commands. The combination of local variables, procedures, and parallelism supports a form of concurrent object-oriented programming. We provide a denotatio...

On Spaces and Navigation In and Out of the Computer

Current work on navigat ion in elect ronic worlds is based on t he assumpt ion t hat geographic and elect ronic worlds are similar enough t o make it possible t o use result s f rom work on environment al psychology and relat ed areas in t he design of elect ronic inf ormat ion spaces. The present paper is an at t empt t o analyze t he underlying assumpt ions behind t his approach in some det a...