Reinhard Muskens (professeur à Tilburg University)

TITRE: A Program for Natural Logic

Many linguists follow May 1985 in positing a level of Logical Form (LF), which is thought to be at the interface between syntax and semantics. If this idea is accepted, one way to formulate a semantic theory is to provide Logical Form representations with a model-theoretic semantics, either directly, or via a translation into some interpreted logical language.

In this talk I will show a second way, not necessarily incompatible with the first, but more in line with the idea that the mind is a computational system. Many Logical Form representations that have been proposed are in fact very close to certain terms of the simply typed lambda calculus. I will assume that Logical Forms are in fact lambda terms and will develop an analytic tableau system that allows for direct reasoning with LFs. This system can be thought of as representing the systematic search for verifying situations that Johnson-Laird and others deem crucial for natural reasoning and its rules are closely connected to properties of operators that have cropped up in the literature on generalised quantifiers and natural logic. It provides a proof-theoretic semantics of natural language that at least in theory is better suited to study processing aspects of thinking and reasoning than the traditional approach is.