40 research outputs found
Inductive and Functional Types in Ludics
Ludics is a logical framework in which types/formulas are modelled by sets of terms with the same computational behaviour. This paper investigates the representation of inductive data types and functional types in ludics. We study their structure following a game semantics approach. Inductive types are interpreted as least fixed points, and we prove an internal completeness result giving an explicit construction for such fixed points. The interactive properties of the ludics interpretation of inductive and functional types are then studied. In particular, we identify which higher-order functions types fail to satisfy type safety, and we give a computational explanation
Infinitary -Calculi from a Linear Perspective (Long Version)
We introduce a linear infinitary -calculus, called
, in which two exponential modalities are available, the
first one being the usual, finitary one, the other being the only construct
interpreted coinductively. The obtained calculus embeds the infinitary
applicative -calculus and is universal for computations over infinite
strings. What is particularly interesting about , is that
the refinement induced by linear logic allows to restrict both modalities so as
to get calculi which are terminating inductively and productive coinductively.
We exemplify this idea by analysing a fragment of built around
the principles of and . Interestingly, it enjoys
confluence, contrarily to what happens in ordinary infinitary
-calculi
Sequentiality vs. Concurrency in Games and Logic
Connections between the sequentiality/concurrency distinction and the
semantics of proofs are investigated, with particular reference to games and
Linear Logic.Comment: 35 pages, appeared in Mathematical Structures in Computer Scienc
Introduction to linear logic and ludics, part II
This paper is the second part of an introduction to linear logic and ludics,
both due to Girard. It is devoted to proof nets, in the limited, yet central,
framework of multiplicative linear logic and to ludics, which has been recently
developped in an aim of further unveiling the fundamental interactive nature of
computation and logic. We hope to offer a few computer science insights into
this new theory
Variable types for meaning assembly: a logical syntax for generic noun phrases introduced by most
This paper proposes a way to compute the meanings associated with sentences
with generic noun phrases corresponding to the generalized quantifier most. We
call these generics specimens and they resemble stereotypes or prototypes in
lexical semantics. The meanings are viewed as logical formulae that can
thereafter be interpreted in your favourite models. To do so, we depart
significantly from the dominant Fregean view with a single untyped universe.
Indeed, our proposal adopts type theory with some hints from Hilbert
\epsilon-calculus (Hilbert, 1922; Avigad and Zach, 2008) and from medieval
philosophy, see e.g. de Libera (1993, 1996). Our type theoretic analysis bears
some resemblance with ongoing work in lexical semantics (Asher 2011; Bassac et
al. 2010; Moot, Pr\'evot and Retor\'e 2011). Our model also applies to
classical examples involving a class, or a generic element of this class, which
is not uttered but provided by the context. An outcome of this study is that,
in the minimalism-contextualism debate, see Conrad (2011), if one adopts a type
theoretical view, terms encode the purely semantic meaning component while
their typing is pragmatically determined
Non uniform (hyper/multi)coherence spaces
In (hyper)coherence semantics, proofs/terms are cliques in (hyper)graphs.
Intuitively, vertices represent results of computations and the edge relation
witnesses the ability of being assembled into a same piece of data or a same
(strongly) stable function, at arrow types. In (hyper)coherence semantics, the
argument of a (strongly) stable functional is always a (strongly) stable
function. As a consequence, comparatively to the relational semantics, where
there is no edge relation, some vertices are missing. Recovering these vertices
is essential for the purpose of reconstructing proofs/terms from their
interpretations. It shall also be useful for the comparison with other
semantics, like game semantics. In [BE01], Bucciarelli and Ehrhard introduced a
so called non uniform coherence space semantics where no vertex is missing. By
constructing the co-free exponential we set a new version of this last
semantics, together with non uniform versions of hypercoherences and
multicoherences, a new semantics where an edge is a finite multiset. Thanks to
the co-free construction, these non uniform semantics are deterministic in the
sense that the intersection of a clique and of an anti-clique contains at most
one vertex, a result of interaction, and extensionally collapse onto the
corresponding uniform semantics.Comment: 32 page