On Meaningfulness and Truth

We show how to construct certain L _{M, T} -type interpreted languages, with each such language containing meaningfulness and truth predicates which apply to itself. These languages are comparable in expressive power to the L _T -type, truth-theoretic languages first considered by Kripke, yet each of our L _{M, T} -type languages possesses the additional advantage that, within it, the meaninglessness of any given meaningless expression can itself be meaningfully expressed. One therefore has, for example, the object level truth (and meaningfulness) of the claim that the strengthened Liar is meaningless.     

Historical Semantic Chaining and Efficient Communication: The Case of Container Names

Semantic categories in the world's languages often reflect a historical process of chaining: A name for one referent is extended to a conceptually related referent, and from there on to other referents, producing a chain of exemplars that all bear the same name. The beginning and end points of such a chain might in principle be rather dissimilar. There is also evidence supporting a contrasting picture: Languages tend to support efficient, informative communication, often through semantic categories in which all exemplars are similar. Here, we explore this tension through computational analyses of existing cross‐language naming and sorting data from the domain of household containers. We find (a) formal evidence for historical semantic chaining, and (b) evidence that systems of categories in this domain nonetheless support near‐optimally efficient communication. Our results demonstrate that semantic chaining is compatible with efficient communication, and they suggest that chaining may be constrained by the functional need for efficient communication.     

Cognitive Metaphor Theory and the Metaphysics of Immediacy

One of the core tenets of cognitive metaphor theory is the claim that metaphors ground abstract knowledge in concrete, first‐hand experience. In this paper, I argue that this grounding hypothesis contains some problematic conceptual ambiguities and, under many reasonable interpretations, empirical difficulties. I present evidence that there are foundational obstacles to defining a coherent and cognitively valid concept of “metaphor” and “concrete meaning,” and some general problems with singling out certain domains of experience as more immediate than others. I conclude from these considerations that whatever the facts are about the comprehension of individual metaphors, the available evidence is incompatible with the notion of an underlying conceptual structure organized according to the immediacy of experience.     

The Idea of a Proof-Theoretic Semantics and the Meaning of the Logical Operations

This is a purely conceptual paper. It aims at presenting and putting into perspective the idea of a proof-theoretic semantics of the logical operations. The first section briefly surveys various semantic paradigms, and Section 2 focuses on one particular paradigm, namely the proof-theoretic semantics of the logical operations. This revised version was published online in June 2006 with corrections to the Cover Date.     

A Complete and Consistent Formal System for Sortals

A formal logical system for sortal quantifiers, sortal identity and (second order) quantification over sortal concepts is formulated. The absolute consistency of the system is proved. A completeness proof for the system is also constructed. This proof is relative to a concept of logical validity provided by a semantics, which assumes as its philosophical background an approach to sortals from a modern form of conceptualism.     

Probability Semantics for Quantifier Logic

By supplying propositional calculus with a probability semantics we showed, in our 1996, that finite stochastic problems can be treated by logic-theoretic means equally as well as by the usual set-theoretic ones. In the present paper we continue the investigation to further the use of logical notions in probability theory. It is shown that quantifier logic, when supplied with a probability semantics, is capable of treating stochastic problems involving countably many trials.     

The semantic/episodic distinction: The case for social information processing

The directed-forgetting paradigm was used in order to dissociate episodic from semantic processes in an impression formation task. Results demonstrate that incongruent behaviors are more prone to manipulations that disrupt episodic memory, whereas congruent behaviors are unaffected by such manipulations. The results suggest that the distinction between episodic and semantic memory processes is central for the understanding of social information processing. An explanation is put forward according to which the incongruency effect, a signature effect of impression formation, is due to an episodic encoding advantage for incongruent behaviors because of their semantically isolated nature, and their impoverished semantic encoding.     

From IF to BI

We take a fresh look at the logics of informational dependence and independence of Hintikka and Sandu and Väänänen, and their compositional semantics due to Hodges. We show how Hodges’ semantics can be seen as a special case of a general construction, which provides a context for a useful completeness theorem with respect to a wider class of models. We shed some new light on each aspect of the logic. We show that the natural propositional logic carried by the semantics is the logic of Bunched Implications due to Pym and O’Hearn, which combines intuitionistic and multiplicative connectives. This introduces several new connectives not previously considered in logics of informational dependence, but which we show play a very natural rôle, most notably intuitionistic implication. As regards the quantifiers, we show that their interpretation in the Hodges semantics is forced, in that they are the image under the general construction of the usual Tarski semantics; this implies that they are adjoints to substitution, and hence uniquely determined. As for the dependence predicate, we show that this is definable from a simpler predicate, of constancy or dependence on nothing. This makes essential use of the intuitionistic implication. The Armstrong axioms for functional dependence are then recovered as a standard set of axioms for intuitionistic implication. We also prove a full abstraction result in the style of Hodges, in which the intuitionistic implication plays a very natural rôle.     

Question answering from structured knowledge sources

We present an implemented approach for domain-restricted question answering from structured knowledge sources, based on robust semantic analysis in a hybrid NLP system architecture. We perform question interpretation and answer extraction in an architecture that builds on a lexical-conceptual structure for question interpretation, which is interfaced with domain-specific concepts and properties in a structured knowledge base. Question interpretation involves a limited amount of domain-specific inferences, and accounts for higher-level quantificational questions. Question interpretation and answer extraction are modular components that interact in clearly defined ways. We derive so-called proto queries from the linguistic representations, which provide partial constraints for answer extraction from the underlying knowledge sources. The search queries we construct from proto queries effectively compute minimal spanning trees from the underlying knowledge sources. Our approach naturally extends to multilingual question answering, and has been developed as a prototype system for two application domains: the domain of Nobel prize winners, and the domain of Language Technology, on the basis of the large ontology underlying the information portal LT World.