1,113 research outputs found
System of spheres-based multiple contractions
We propose a new class of multiple contraction operations — the
system of spheres-based multiple contractions — which are a generalization
of Grove’s system of spheres-based (singleton) contractions to the case of
contractions by (possibly non-singleton) sets of sentences. Furthermore, we
show that this new class of functions is a subclass of the class of the partial
meet multiple contractions.info:eu-repo/semantics/publishedVersio
Possible worlds semantics for partial meet multiple contraction
In the logic of theory change, the standard model is AGM, proposed
by Alchourrón et al. (J Symb Log 50:510–530, 1985). This paper focuses
on the extension of AGM that accounts for contractions of a theory by
a set of sentences instead of only by a single sentence. Hansson (Theoria
55:114–132, 1989), Fuhrmann and Hansson (J Logic Lang Inf 3:39–74, 1994)
generalized Partial Meet Contraction to the case of contractions by (possibly
non-singleton) sets of sentences. In this paper we present the possible worlds
semantics for partial meet multiple contractions.info:eu-repo/semantics/publishedVersio
Residual contraction
In this paper, we propose and axiomatically characterize residual
contractions, a new kind of contraction operators for belief bases. We establish
that the class of partial meet contractions is a strict subclass of the class of
residual contractions. We identify an extra condition that may be added to
the definition of residual contractions, which is such that the class of residual
contractions that satisfy it coincides with the class of partial meet contrac tions. We investigate the interrelations in the sense of (strict) inclusion among
the class of residual contractions and other classes of well known contraction
operators for belief bases.info:eu-repo/semantics/publishedVersio
Epistemic entrenchment-based multiple contractions
In this article we present a new class of multiple contraction functions—the epistemic entrenchment-based multiple contractions—which are a generalization of the epistemic
entrenchment-based contractions (Gardenfors, 1988; G ¨ ardenfors & Makinson, 1988) to the case of ¨
contractions by (possibly nonsingleton) sets of sentences and provide an axiomatic characterization
for that class of functions. Moreover, we show that the class of epistemic entrenchment-based multi ple contractions coincides with the class of system of spheres-based multiple contractions introduced
in Ferme & Reis (2012).info:eu-repo/semantics/publishedVersio
- …