Expressing the Behavior of Three Very Different Concurrent Systems by Using Natural Extensions of Separation Logic

Separation Logic is a non-classical logic used to verify pointer-intensive code. In this paper, however, we show that Separation Logic, along with its natural extensions, can also be used as a specification language for concurrent-system design. To do so, we express the behavior of three very different concurrent systems: a Subway, a Stopwatch, and a 2x2 Switch. The Subway is originally implemented in LUSTRE, the Stopwatch in Esterel, and the 2x2 Switch in Bluespec

Towards a Historical Notion of 'Turing-the Father of Computer Science'

© 2015 EDGAR G. DAYLIGHT. In the popular imagination, the relevance of Turing's theoretical ideas to people producing actual machines was significant and appreciated by everybody involved in computing from the moment he published his 1936 paper ‘On Computable Numbers’. Careful historians are aware that this popular conception is deeply misleading. We know from previous work by Campbell-Kelly, Aspray, Akera, Olley, Priestley, Daylight, Mounier-Kuhn, Haigh, and others that several computing pioneers, including Aiken, Eckert, Mauchly, and Zuse, did not depend on (let alone were they aware of) Turing's 1936 universal-machine concept. Furthermore, it is not clear whether any substance in von Neumann's celebrated 1945 ‘First Draft Report on the EDVAC’ is influenced in any identifiable way by Turing's work. This raises the questions: (i) When does Turing enter the field? (ii) Why did the Association for Computing Machinery (ACM) honor Turing by associating his name to ACM's most prestigious award, the Turing Award? Previous authors have been rather vague about these questions, suggesting some date between 1950 and the early 1960s as the point at which Turing is retroactively integrated into the foundations of computing and associating him in some way with the movement to develop something that people call computer science. In this paper, based on detailed examination of hitherto overlooked primary sources, attempts are made to reconstruct networks of scholars and ideas prevalent in the 1950s, and to identify a specific group of (Formula presented.) actors interested in theorizing about computations in computers and attracted to the idea of language as a frame in which to understand computation. By going back to Turing's 1936 paper and, more importantly, to re-cast versions of Turing's work published during the 1950s (Rosenbloom, Kleene, Markov), I identify the factors that made this group of scholars particularly interested in Turing's work and provided the original vector by which Turing became to be appreciated in retrospect as the father of computer science.status: publishe

Turing Tales

Edgar Daylight's rather provocative theme in this book is that many high-profile computer scientists do not consistently distinguish between their favorite mathematical concepts and the representations thereof in the real world. This leads to mistakes. Daylight introduces seemingly small but useful distinctions. As a result, technical corrections are put forth in connection with formal verification, computer viruses, and program transformation systems. Even mathematics isn't free from conceptual flaws. Raymond Boute scrutinizes several unsound treatments of the function concept and connects his findings with computer science proper. Daylight also rectifies the romantic idea that "Turing invented the modern computer." Contrary to public opinion today, most computer pioneers were not trying to build a practical realization of a universal Turing machine. An exception in this regard is the Dutch computer builder Willem van der Poel, whose story is told here in English for the first time. Arhur C. Fleck rounds out the historiographical weight of this book with his valuable reflections on the history of programming languages and Turing-Award winners.nrpages: 264status: publishe