42,979 research outputs found
Dynamic epistemic logics for abstract argumentation
AbstractThis paper introduces a multi-agent dynamic epistemic logic for abstract argumentation. Its main motivation is to build a general framework for modelling the dynamics of a debate, which entails reasoning about goals, beliefs, as well as policies of communication and information update by the participants. After locating our proposal and introducing the relevant tools from abstract argumentation, we proceed to build a three-tiered logical approach. At the first level, we use the language of propositional logic to encode states of a multi-agent debate. This language allows to specify which arguments any agent is aware of, as well as their subjective justification status. We then extend our language and semantics to that of epistemic logic, in order to model individuals' beliefs about the state of the debate, which includes uncertainty about the information available to others. As a third step, we introduce a framework of dynamic epistemic logic and its semantics, which is essentially based on so-called event models with factual change. We provide completeness results for a number of systems and show how existing formalisms for argumentation dynamics and unquantified uncertainty can be reduced to their semantics. The resulting framework allows reasoning about subtle epistemic and argumentative updates—such as the effects of different levels of trust in a source—and more in general about the epistemic dimensions of strategic communication
A Dynamic Epistemic Logic for Abstract Argumentation
This paper introduces a multi-agent dynamic epistemic logic for abstract argumenta-
tion. Its main motivation is to build a general framework for modelling the dynamics
of a debate, which entails reasoning about goals, beliefs, as well as policies of com-
munication and information update by the participants. After locating our proposal
and introducing the relevant tools from abstract argumentation, we proceed to build a
three-tiered logical approach. At the first level, we use the language of propositional
logic to encode states of a multi-agent debate. This language allows to specify which
arguments any agent is aware of, as well as their subjective justification status. We
then extend our language and semantics to that of epistemic logic, in order to model
individuals’ beliefs about the state of the debate, which includes uncertainty about the
information available to others. As a third step, we introduce a framework of dynamic
epistemic logic and its semantics, which is essentially based on so-called event models
with factual change. We provide completeness results for a number of systems and
show how existing formalisms for argumentation dynamics and unquantified uncerSynthese
tainty can be reduced to their semantics. The resulting framework allows reasoning
about subtle epistemic and argumentative updates—such as the effects of different
levels of trust in a source—and more in general about the epistemic dimensions of
strategic communication
Dynamics in Formal Argumentation
Centre for Intelligent Systems and their ApplicationsIn this thesis we are concerned with the role of formal argumentation in artificial intelligence, in particular in the field of knowledge engineering. The intuition behind argumentation is that one can reason with imperfect information by constructing and weighing up arguements intended to give support in favour or against alternative conclusions. In dynamic argumentation, such arguements may be revised and strengthened in order yo increase to decrease the acceptability of controversial positions.
This thesis studies the theory, architecture, development and applications of formal arguementation systems from the procedural perspective of actually generating argumentation processes. First, the types of problems that can be tackled via the argumentation paradigm in knowledge engineering are characterised. Second, an abstract formal framework are built from an underlying set of axioms, represented here as executatble logic programs. Finally an architecture for dynamic arguementation systems is defined, and domain-specific applications are presented within different domaind, thus grounding problems with very distinctive characteristics into a similar source in argumentation.
The methods and definitions desribed in this thesis have been assessed on various bases, including the reconstruction of informal arguements and of arguments captured by existing formalisms, the relation between our framework and these formalisms, and examples of dynamic argumentation applications in the safety-engineering and multi-agent domains
Abstract Argumentation / Persuasion / Dynamics
The act of persuasion, a key component in rhetoric argumentation, may be
viewed as a dynamics modifier. We extend Dung's frameworks with acts of
persuasion among agents, and consider interactions among attack, persuasion and
defence that have been largely unheeded so far. We characterise basic notions
of admissibilities in this framework, and show a way of enriching them through,
effectively, CTL (computation tree logic) encoding, which also permits
importation of the theoretical results known to the logic into our
argumentation frameworks. Our aim is to complement the growing interest in
coordination of static and dynamic argumentation.Comment: Arisaka R., Satoh K. (2018) Abstract Argumentation / Persuasion /
Dynamics. In: Miller T., Oren N., Sakurai Y., Noda I., Savarimuthu B., Cao
Son T. (eds) PRIMA 2018: Principles and Practice of Multi-Agent Systems.
PRIMA 2018. Lecture Notes in Computer Science, vol 11224. Springer, Cha
Argument-based Belief in Topological Structures
This paper combines two studies: a topological semantics for epistemic
notions and abstract argumentation theory. In our combined setting, we use a
topological semantics to represent the structure of an agent's collection of
evidence, and we use argumentation theory to single out the relevant sets of
evidence through which a notion of beliefs grounded on arguments is defined. We
discuss the formal properties of this newly defined notion, providing also a
formal language with a matching modality together with a sound and complete
axiom system for it. Despite the fact that our agent can combine her evidence
in a 'rational' way (captured via the topological structure), argument-based
beliefs are not closed under conjunction. This illustrates the difference
between an agent's reasoning abilities (i.e. the way she is able to combine her
available evidence) and the closure properties of her beliefs. We use this
point to argue for why the failure of closure under conjunction of belief
should not bear the burden of the failure of rationality.Comment: In Proceedings TARK 2017, arXiv:1707.0825
An Abstract Look at Awareness Models and Their Dynamics
This work builds upon a well-established research tradition on modal logics
of awareness. One of its aims is to export tools and techniques to other areas
within modal logic. To this end, we illustrate a number of significant bridges
with abstract argumentation, justification logics, the epistemic logic of
knowing-what and deontic logic, where basic notions and definitional concepts
can be expressed in terms of the awareness operator combined with the box
modality. Furthermore, these conceptual links point to interesting properties
of awareness sets beyond those standardly assumed in awareness logics, i.e.
positive and negative introspection. We show that the properties we list are
characterised by corresponding canonical formulas, so as to obtain a series of
off-the-shelf axiomatisations for them. As a second focus, we investigate the
general dynamics of this framework by means of event models. Of specific
interest in this context is to know under which conditions, given a model that
satisfies some property, the update with an event model keeps it within the
intended class. This is known as the closure problem in general dynamic
epistemic logics. As a main contribution, we prove a number of closure theorems
providing sufficient conditions for the preservation of our properties. Again,
these results enable us to axiomatize our dynamic logics by means of reduction
axioms.Comment: In Proceedings TARK 2023, arXiv:2307.0400
Reasoning about Action: An Argumentation - Theoretic Approach
We present a uniform non-monotonic solution to the problems of reasoning
about action on the basis of an argumentation-theoretic approach. Our theory is
provably correct relative to a sensible minimisation policy introduced on top
of a temporal propositional logic. Sophisticated problem domains can be
formalised in our framework. As much attention of researchers in the field has
been paid to the traditional and basic problems in reasoning about actions such
as the frame, the qualification and the ramification problems, approaches to
these problems within our formalisation lie at heart of the expositions
presented in this paper
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