5,429 research outputs found
A reconstruction of the multipreference closure
The paper describes a preferential approach for dealing with exceptions in
KLM preferential logics, based on the rational closure. It is well known that
the rational closure does not allow an independent handling of the inheritance
of different defeasible properties of concepts. Several solutions have been
proposed to face this problem and the lexicographic closure is the most notable
one. In this work, we consider an alternative closure construction, called the
Multi Preference closure (MP-closure), that has been first considered for
reasoning with exceptions in DLs. Here, we reconstruct the notion of MP-closure
in the propositional case and we show that it is a natural variant of Lehmann's
lexicographic closure. Abandoning Maximal Entropy (an alternative route already
considered but not explored by Lehmann) leads to a construction which exploits
a different lexicographic ordering w.r.t. the lexicographic closure, and
determines a preferential consequence relation rather than a rational
consequence relation. We show that, building on the MP-closure semantics,
rationality can be recovered, at least from the semantic point of view,
resulting in a rational consequence relation which is stronger than the
rational closure, but incomparable with the lexicographic closure. We also show
that the MP-closure is stronger than the Relevant Closure.Comment: 57 page
Indicative Conditionals and Dynamic Epistemic Logic
Recent ideas about epistemic modals and indicative conditionals in formal
semantics have significant overlap with ideas in modal logic and dynamic
epistemic logic. The purpose of this paper is to show how greater interaction
between formal semantics and dynamic epistemic logic in this area can be of
mutual benefit. In one direction, we show how concepts and tools from modal
logic and dynamic epistemic logic can be used to give a simple, complete
axiomatization of Yalcin's [16] semantic consequence relation for a language
with epistemic modals and indicative conditionals. In the other direction, the
formal semantics for indicative conditionals due to Kolodny and MacFarlane [9]
gives rise to a new dynamic operator that is very natural from the point of
view of dynamic epistemic logic, allowing succinct expression of dependence (as
in dependence logic) or supervenience statements. We prove decidability for the
logic with epistemic modals and Kolodny and MacFarlane's indicative conditional
via a full and faithful computable translation from their logic to the modal
logic K45.Comment: In Proceedings TARK 2017, arXiv:1707.0825
Conditionals and modularity in general logics
In this work in progress, we discuss independence and interpolation and
related topics for classical, modal, and non-monotonic logics
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