Fifty years of Hoare's Logic

We present a history of Hoare's logic.Comment: 79 pages. To appear in Formal Aspects of Computin

Towards a machine-independent transput section

If the transput section of an ALGOL-68 compiler is to be portable, it must be described in such a way that it is clear which aspects are machine-dependent, and which are not. There should be a clear set of primitives underlying the transput. In this report, a description is proposed which can really be used as an implementation model: the transput is described in pseudo-ALGOL 68, except for the underlying primitives, whose semantics are given in some kind of formalized English. The state of this model is by no means definitive, but may serve as a start for further discussion

Introduction to the Literature on Programming Language Design

This is an introduction to the literature on programming language design and related topics. It is intended to cite the most important work, and to provide a place for students to start a literature search

A Variant of Earley Parsing

The Earley algorithm is a widely used parsing method in natural language processing applications. We introduce a variant of Earley parsing that is based on a ``delayed'' recognition of constituents. This allows us to start the recognition of a constituent only in cases in which all of its subconstituents have been found within the input string. This is particularly advantageous in several cases in which partial analysis of a constituent cannot be completed and in general in all cases of productions sharing some suffix of their right-hand sides (even for different left-hand side nonterminals). Although the two algorithms result in the same asymptotic time and space complexity, from a practical perspective our algorithm improves the time and space requirements of the original method, as shown by reported experimental results.Comment: 12 pages, 1 Postscript figure, uses psfig.tex and llncs.st