Two Decades of Maude

This paper is a tribute to José Meseguer, from the rest of us in the Maude team, reviewing the past, the present, and the future of the language and system with which we have been working for around two decades under his leadership. After reviewing the origins and the language's main features, we present the latest additions to the language and some features currently under development. This paper is not an introduction to Maude, and some familiarity with it and with rewriting logic are indeed assumed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Unifying type systems for mobile processes

We present a unifying framework for type systems for process calculi. The core of the system provides an accurate correspondence between essentially functional processes and linear logic proofs; fragments of this system correspond to previously known connections between proofs and processes. We show how the addition of extra logical axioms can widen the class of typeable processes in exchange for the loss of some computational properties like lock-freeness or termination, allowing us to see various well studied systems (like i/o types, linearity, control) as instances of a general pattern. This suggests unified methods for extending existing type systems with new features while staying in a well structured environment and constitutes a step towards the study of denotational semantics of processes using proof-theoretical methods

Of epistemic tools: musical instruments as cognitive extensions

This paper explores the differences in the design and performance of acoustic and new digital musical instruments, arguing that with the latter there is an increased encapsulation of musical theory. The point of departure is the phenomenology of musical instruments, which leads to the exploration of designed artefacts as extensions of human cognition – as scaffolding onto which we delegate parts of our cognitive processes. The paper succinctly emphasises the pronounced epistemic dimension of digital instruments when compared to acoustic instruments. Through the analysis of material epistemologies it is possible to describe the digital instrument as an epistemic tool: a designed tool with such a high degree of symbolic pertinence that it becomes a system of knowledge and thinking in its own terms. In conclusion, the paper rounds up the phenomenological and epistemological arguments, and points at issues in the design of digital musical instruments that are germane due to their strong aesthetic implications for musical culture

Platform Dependent Verification: On Engineering Verification Tools for 21st Century

The paper overviews recent developments in platform-dependent explicit-state LTL model checking.Comment: In Proceedings PDMC 2011, arXiv:1111.006

Challenges in computational lower bounds

We draw two incomplete, biased maps of challenges in computational complexity lower bounds

A universe of processes and some of its guises

Our starting point is a particular `canvas' aimed to `draw' theories of physics, which has symmetric monoidal categories as its mathematical backbone. In this paper we consider the conceptual foundations for this canvas, and how these can then be converted into mathematical structure. With very little structural effort (i.e. in very abstract terms) and in a very short time span the categorical quantum mechanics (CQM) research program has reproduced a surprisingly large fragment of quantum theory. It also provides new insights both in quantum foundations and in quantum information, and has even resulted in automated reasoning software called `quantomatic' which exploits the deductive power of CQM. In this paper we complement the available material by not requiring prior knowledge of category theory, and by pointing at connections to previous and current developments in the foundations of physics. This research program is also in close synergy with developments elsewhere, for example in representation theory, quantum algebra, knot theory, topological quantum field theory and several other areas.Comment: Invited chapter in: "Deep Beauty: Understanding the Quantum World through Mathematical Innovation", H. Halvorson, ed., Cambridge University Press, forthcoming. (as usual, many pictures

Approaching Utopia: Strong Truthfulness and Externality-Resistant Mechanisms

We introduce and study strongly truthful mechanisms and their applications. We use strongly truthful mechanisms as a tool for implementation in undominated strategies for several problems,including the design of externality resistant auctions and a variant of multi-dimensional scheduling