1,048 research outputs found
Semantic Ambiguity and Perceived Ambiguity
I explore some of the issues that arise when trying to establish a connection
between the underspecification hypothesis pursued in the NLP literature and
work on ambiguity in semantics and in the psychological literature. A theory of
underspecification is developed `from the first principles', i.e., starting
from a definition of what it means for a sentence to be semantically ambiguous
and from what we know about the way humans deal with ambiguity. An
underspecified language is specified as the translation language of a grammar
covering sentences that display three classes of semantic ambiguity: lexical
ambiguity, scopal ambiguity, and referential ambiguity. The expressions of this
language denote sets of senses. A formalization of defeasible reasoning with
underspecified representations is presented, based on Default Logic. Some
issues to be confronted by such a formalization are discussed.Comment: Latex, 47 pages. Uses tree-dvips.sty, lingmacros.sty, fullname.st
Designing Normative Theories for Ethical and Legal Reasoning: LogiKEy Framework, Methodology, and Tool Support
A framework and methodology---termed LogiKEy---for the design and engineering
of ethical reasoners, normative theories and deontic logics is presented. The
overall motivation is the development of suitable means for the control and
governance of intelligent autonomous systems. LogiKEy's unifying formal
framework is based on semantical embeddings of deontic logics, logic
combinations and ethico-legal domain theories in expressive classic
higher-order logic (HOL). This meta-logical approach enables the provision of
powerful tool support in LogiKEy: off-the-shelf theorem provers and model
finders for HOL are assisting the LogiKEy designer of ethical intelligent
agents to flexibly experiment with underlying logics and their combinations,
with ethico-legal domain theories, and with concrete examples---all at the same
time. Continuous improvements of these off-the-shelf provers, without further
ado, leverage the reasoning performance in LogiKEy. Case studies, in which the
LogiKEy framework and methodology has been applied and tested, give evidence
that HOL's undecidability often does not hinder efficient experimentation.Comment: 50 pages; 10 figure
Anaphora and Discourse Structure
We argue in this paper that many common adverbial phrases generally taken to
signal a discourse relation between syntactically connected units within
discourse structure, instead work anaphorically to contribute relational
meaning, with only indirect dependence on discourse structure. This allows a
simpler discourse structure to provide scaffolding for compositional semantics,
and reveals multiple ways in which the relational meaning conveyed by adverbial
connectives can interact with that associated with discourse structure. We
conclude by sketching out a lexicalised grammar for discourse that facilitates
discourse interpretation as a product of compositional rules, anaphor
resolution and inference.Comment: 45 pages, 17 figures. Revised resubmission to Computational
Linguistic
An Adaptive Logic for the Formal Explication of Scalar Implicatures
Hearers get at the intended meaning of uncooperative utterances (i.e. utterances that conflict with the prescriptions laid down by the Gricean maxims) by pragmatically deriving sentences that reconcile these utterances with the maxims. Such pragmatic derivations are made according to pragmatic rules called implicatures. As they are pragmatic in nature, the conclusions drawn by applying implicatures remain uncertain. In other words, they may have to be withdrawn in view of further information. Because of this last feature, Levinson argued that implicatures should be formally modeled as non–monotonic or default rules of inference. In this paper, I will do exactly this: by relying on the Adaptive Logics Programme, I will provide a formal explication of implicatures as default inference rules. More specifically, I will do so for a particular kind of implicatures, viz scalar implicatures
Defeasible Reasoning with Knowledge Graphs
Human knowledge is subject to uncertainties, imprecision, incompleteness and
inconsistencies. Moreover, the meaning of many everyday terms is dependent on
the context. That poses a huge challenge for the Semantic Web. This paper
introduces work on an intuitive notation and model for defeasible reasoning
with imperfect knowledge, and relates it to previous work on argumentation
theory. PKN is to N3 as defeasible reasoning is to deductive logic. Further
work is needed on an intuitive syntax for describing reasoning strategies and
tactics in declarative terms, drawing upon the AIF ontology for inspiration.
The paper closes with observations on symbolic approaches in the era of large
language models.Comment: Accepted for: Knowledge Graph and Semantic Web Conference
(KGSWC-2023), 13-15 September, 2023, Zaragoza, Spai
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