Title
A Semantical Analysis of Focusing and Contraction in Intuitionistic Logic.
Abstract
Focusing is a proof-theoretic device to structure proof search in the sequent calculus: it provides a normal form to cut-free proofs in which the application of invertible and non-invertible inference rules is structured in two separate and disjoint phases. Although stemming from proof-search considerations, focusing has not been thoroughly investigated in actual theorem proving, in particular w.r.t. termination. We present a contraction-free (and hence terminating) focused multi-succedent sequent calculus for propositional intuitionistic logic, which refines the G4ip calculus in the tradition of Vorob'ev, Hudelmeier and Dyckhoff. We prove completeness of the calculus semantically and argue that this offers a viable alternative to other more syntactical means.
Year
DOI
Venue
2015
10.3233/FI-2015-1253
FUNDAMENTA INFORMATICAE
DocType
Volume
Issue
Journal
140
3-4
ISSN
Citations 
PageRank 
0169-2968
1
0.36
References 
Authors
18
3
Name
Order
Citations
PageRank
Alessandro Avellone1637.66
Camillo Fiorentini212121.00
Alberto Momigliano322124.78