Abstract not found

Traditional denotational semantics assigns radically different meanings to one and the same phrase depending on the rest of the programming language. If the language is purely functional, the denotation of a numeral is a function from environments to integers. But, in a functional language with imperative control operators, a numeral denotes a function from environments and continuations to integers. This paper introduces a new format for denotational language specifications, extended direct semantics, that accommodates orthogonal extensions of a language without changing the denotations of existing phrases. An extended direct semantics always maps a numeral to the same denotation: the injection of the corresponding number into the domain of values. In general, the denotation of a phrase in a functional language is always a projection of the denotation of the same phrase in the semantics of an extended language---no matter what the extension is. Based on extended direct semantics, i...

A specification formalism with parameterisation of an arbitrary order is presented. It is given a denotational-style semantics, accompanied by an inference system for proving that an object satisfies a specification. The inference system incorporates, but is not limited to, a clearly identified type-checking component. Special effort is made to carefully distinguish between parameterised specifications, which denote functions yielding classes of objects, and specifications of parameterised objects, which denote classes of functions yielding objects. To deal with both of these in a uniform framework, it was convenient to view specifications, which specify objects, as objects themselves, and to introduce a notion of a specification of specifications. The formalism includes the basic specification-building operations of the ASL specification language. This choice, however, is orthogonal to the new ideas presented. The formalism is also institution-independent, although this iss...

this paper to the legal symbolic types only we obtain the following theorem.

Abstract. Formal descriptions of syntax are quite popular: regular and context-free grammars have become accepted as useful for documenting the syntax of programming languages, as well as for generating efficient parsers; attribute grammars allow parsing to be linked with typechecking and code generation; and regular expressions are extensively used for searching and transforming text. In contrast, formal semantic descriptions are widely regarded as being of interest only to theoreticians. This paper surveys the main frameworks available for describing the dynamic semantics of programming languages. It assesses the potential and actual uses of semantic descriptions, and considers practical aspects, such as comprehensibility, modularity, and extensibility, which are especially significant when describing full-scale languages. It concludes by suggesting that the provision of mature tools for transforming practical semantic descriptions into reasonably efficient compilers and interpreters would significantly increase the popularity of formal semantics. The paper is intended to be accessible to all computer scientists. Familiarity with the details of particular semantic frameworks is not required, although some understanding of the general concepts of formal semantics is assumed. 1

. The walking-(and searching-) pattern generator of stick insects, a modular system composed of reflex chains and edogenous oscillators. Biological Cybernetics, 69:305-- 317, 1993. [12] Francoise Beaufays and Eric A. Wan. Relating real-time backpropagation and backpropagation-through-time: An application of flow graph interreciprocity. Neural Computation, 6:296--306, 1994. [13] Randall D. Beer. Intelligence as Adaptive Behavior: An Experiment in Computational Neuroethology. Academic Press, 1990. 211 212 BIBLIOGRAPHY [14] Randall D. Beer, Hillel J. Chiel, Roger D. Quinn, Kenneth S. Espenschied, and Patrick Larsson. A distributed neural network architecture for hexapod robot locomotion. Neural Computation, 4:356--365, 1992. [15] Randall D. Beer, Hillel J. Chiel, and Leon S. Sterling. An artificial insect. American Scientist, 79:444--452, 1991. [16] Geoffrey Black. Control of an overhe

This document contains the annotated VDM bibliography with more than 600 entries related to VDM. The listed items come from a wide variety of sources, but unfortunately the list is not yet exhaustive. This version contains a partitioning of entries into categories of subjects. A little introduction and background material is given, and some advice on how to get started with VDM (for newcomers). This document was previously edited at the Technical University of Denmark by Dines Bjørner (subject editor) and Annie Rasmussen (copy editor). The editor regrets that he is unable to supply hard copy of items referenced in the bibliography. Document History Zero'eth version of this document issued on 19. March 1987. Printed in 200 copies. Some 150 distributed, courtesy DDC, at the CEC VDM-Europe Symposium '87: VDM: A Formal Method at Work, March, 1987, Brussels. The first version was distributed at the CEC VDM-Europe Symposium '88: VDM --- The Way Ahead, September 1988, Dublin. The second ve...