Focusing in Asynchronous Games

Game semantics provides an interactive point of view on proofs, which enables one to describe precisely their dynamical behavior during cut elimination, by considering formulas as games on which proofs induce strategies. We are specifically interested here in relating two such semantics of linear logic, of very different flavor, which both take in account concurrent features of the proofs: asynchronous games and concurrent games. Interestingly, we show that associating a concurrent strategy to an asynchronous strategy can be seen as a semantical counterpart of the focusing property of linear logic

Focalisation and Classical Realisability (version with appendices)

The original publication is avalaible at : www.springerlink.comInternational audienceWe develop a polarised variant of Curien and Herbelin's lambda-bar-mu-mu-tilde calculus suitable for sequent calculi that admit a focalising cut elimination (i.e. whose proofs are focalised when cut-free), such as Girard's classical logic LC or linear logic. This gives a setting in which Krivine's classical realisability extends naturally (in particular to call-by-value), with a presentation in terms of orthogonality. We give examples of applications to the theory of programming languages

The efficacy of adding short-term psychodynamic psychotherapy to antidepressants in the treatment of depression:A systematic review and meta-analysis of individual participant data

Contains fulltext : 220185.pdf (Publisher’s version ) (Closed access)Purpose: We examined the efficacy of adding short-term psychodynamic psychotherapy (STPP) to antidepressants in the treatment of depression by means of a systematic review and meta-analysis of individual participant data, which is currently considered the most reliable method for evidence synthesis. Results: A thorough systematic literature search resulted in 7 studies comparing combined treatment of antidepressants and STPP versus antidepressant mono-therapy (n = 3) or versus antidepressants and brief supportive psychotherapy (n = 4). Individual participant data were obtained for all these studies and totaled 482 participants. Across the total sample of studies, combined treatment of antidepressants and STPP was found significantly more efficacious in terms of depressive symptom levels at both post-treatment (Cohen's d = 0.26, SE = 0.10, p = .01) and follow-up (d = 0.50, SE = 0.10, p < .001). This effect was most apparent at follow-up and in studies examining STPP's specific treatment efficacy. Effects were still apparent in analyses that controlled for risk of bias and STPP quality in the primary studies. Conclusions: These findings support the evidence-base of adding STPP to antidepressants in the treatment of depression. However, further studies are needed, particularly assessing outcome measures other than depression and cost-effectiveness, as well as examining the relative merits of STPP versus other psychotherapies as added to antidepressants.10 p

Polarized Substructural Session Types

Abstract. The deep connection between session-typed concurrency and linear logic is embodied in the language SILL that integrates functional and message-passing concurrent programming. The exacting nature of linear typing provides strong guarantees, such as global progress, absence of deadlock, and race freedom, but it also requires explicit resource man-agement by the programmer. This burden is alleviated in an affine type system where resources need not be used, relying on a simple form of garbage collection. In this paper we show how to effectively support both linear and affine typing in a single language, in addition to the already present unre-stricted (intuitionistic) types. The approach, based on Benton’s adjoint construction, suggests that the usual distinction between synchronous and asynchronous communication can be viewed through the lens of modal logic. We show how polarizing the propositions into positive and negative connectives allows us to elegantly express synchronization in the type instead of encoding it by extra-logical means.

LINK: a Proof Environment based on Proof nets

Colloque avec actes et comité de lecture. internationale.International audienceLINK is a proof environment including proof nets-based provers for multiplicative linear logics: mixed linear logic, or recently called non-commutative logic (MNL), commutative linear logic (MLL) and non-commutative (or cyclic) linear logic (MCyLL). Its main characteristic is the provability analysis through automatic proof nets construction that is a powerful alternative to deal with resource management in proof search. These provers can be also seen as implementations of new connection methods for these linear logic fragments

Concurrent Construction of Proof-Nets

The functional paradigm of computation has been widely investigated and given a solid mathematical foundation, initiated with the Curry-Howard isomorphism, then elaborated and extended in multiple ways. However, this paradigm is inadequate to capture many useful programming intuitions, arising in particular in the development of applications integrating distributed, autonomous components. Indeed, in this context, non-determinism and true concurrency are the rule, whereas functional programming stresses determinism, and, although it allows some degree of concurrency, it is more as a &quot;nice feature to have&quot; rather than a primary assumption. This paper is part of a program the ambition of which is to provide a logical foundation to a set of programming intuitions which, until now, have not been adequately accounted for. In particular, we are interested in the intuitions which lie behind the concept of transaction, a powerful and essential concept in distributed component-based application development. This concept is independent of the application domain and usually captured in an abstract form in middleware architectural layers. We claim here that proof-construction, and more precisely proof-net construction in Linear Logic, offers the adequate basis for our purpose. We outline the relation, which is of the same nature as the Curry-Howard isomorphism, between transactional concepts and mechanisms on one hand, and proof-net construction on the other. Finally, we describe an algorithm which performs concurrent proof-net construction, where each expansion step is viewed as a transaction. Conflicts between such transactions are minimised using general topological properties of proof-nets, based on a variant of the notion of &quot;domination tree&quot;, introduced and proved here