113 research outputs found
Glueability of Resource Proof-Structures: Inverting the Taylor Expansion
A Multiplicative-Exponential Linear Logic (MELL) proof-structure can be expanded into a set of resource proof-structures: its Taylor expansion. We introduce a new criterion characterizing those sets of resource proof-structures that are part of the Taylor expansion of some MELL proof-structure, through a rewriting system acting both on resource and MELL proof-structures
Canonical Proof nets for Classical Logic
Proof nets provide abstract counterparts to sequent proofs modulo rule
permutations; the idea being that if two proofs have the same underlying
proof-net, they are in essence the same proof. Providing a convincing proof-net
counterpart to proofs in the classical sequent calculus is thus an important
step in understanding classical sequent calculus proofs. By convincing, we mean
that (a) there should be a canonical function from sequent proofs to proof
nets, (b) it should be possible to check the correctness of a net in polynomial
time, (c) every correct net should be obtainable from a sequent calculus proof,
and (d) there should be a cut-elimination procedure which preserves
correctness. Previous attempts to give proof-net-like objects for propositional
classical logic have failed at least one of the above conditions. In [23], the
author presented a calculus of proof nets (expansion nets) satisfying (a) and
(b); the paper defined a sequent calculus corresponding to expansion nets but
gave no explicit demonstration of (c). That sequent calculus, called LK\ast in
this paper, is a novel one-sided sequent calculus with both additively and
multiplicatively formulated disjunction rules. In this paper (a self-contained
extended version of [23]), we give a full proof of (c) for expansion nets with
respect to LK\ast, and in addition give a cut-elimination procedure internal to
expansion nets - this makes expansion nets the first notion of proof-net for
classical logic satisfying all four criteria.Comment: Accepted for publication in APAL (Special issue, Classical Logic and
Computation
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
A Characterisation of Medial as Rewriting Rule
International audienceMedial is an inference rule scheme that appears in various deductive systems based on deep inference. In this paper we investigate the properties of medial as rewriting rule independently from logic. We present a graph theoretical criterion for checking whether there exists a medial rewriting path between two formulas. Finally, we return to logic and apply our criterion for giving a combinatorial proof for a decomposition theorem, i.e., proof theoretical statement about syntax
Gluing resource proof-structures: inhabitation and inverting the Taylor expansion
A Multiplicative-Exponential Linear Logic (MELL) proof-structure can be
expanded into a set of resource proof-structures: its Taylor expansion. We
introduce a new criterion characterizing those sets of resource
proof-structures that are part of the Taylor expansion of some MELL
proof-structure, through a rewriting system acting both on resource and MELL
proof-structures. As a consequence, we also prove semi-decidability of the type
inhabitation problem for cut-free MELL proof-structures.Comment: arXiv admin note: substantial text overlap with arXiv:1910.0793
Linear Logic by Levels and Bounded Time Complexity
We give a new characterization of elementary and deterministic polynomial
time computation in linear logic through the proofs-as-programs correspondence.
Girard's seminal results, concerning elementary and light linear logic, achieve
this characterization by enforcing a stratification principle on proofs, using
the notion of depth in proof nets. Here, we propose a more general form of
stratification, based on inducing levels in proof nets by means of indexes,
which allows us to extend Girard's systems while keeping the same complexity
properties. In particular, it turns out that Girard's systems can be recovered
by forcing depth and level to coincide. A consequence of the higher flexibility
of levels with respect to depth is the absence of boxes for handling the
paragraph modality. We use this fact to propose a variant of our polytime
system in which the paragraph modality is only allowed on atoms, and which may
thus serve as a basis for developing lambda-calculus type assignment systems
with more efficient typing algorithms than existing ones.Comment: 63 pages. To appear in Theoretical Computer Science. This version
corrects minor fonts problems from v
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