Evening lectures:

Scheduled	Lecturer	Title	Description
Tuesday, August 18, 1998 20.00 - 21.00	Elisabet Engdahl	"On Grammar Architecture"	Theoretical linguists like to develop models for the way linguistc knowledge, or grammar, is organised. In my talk I will look at some leading ideas in grammar architecture, identifying some fundamental assumptions about the nature of building blocks and how they can be put together. As in other areas of architecture, we will find both traditionalists and iconoclasts.
Thursday, August 20, 1998 20.00 - 21.00	Moshe Vardi	"Alternating Automata - Unifying Truth and Validity Checking for Temporal Logics"	"Spinoza Lecture 1998" We describe an automata-theoretic approach to the automated checking of truth and validity for temporal logics. The basic idea underlying this approach is that for any formula we can construct an alternating automaton that accepts precisely the models of the formula. For linear temporal logics the automaton runs on infinite words while for branching temporal logics the automaton runs in infinite trees. The simple combinatorial structures that emerge from the automata-theoretic approach decouple the logical and algorithmic components of truth and validity checking and yield clean and essentially optimal algorithms for both problems.
Tuesday, August 25, 1998 20.00 - 21.00	Eric Laporte	"Lexical Disambiguation"	In any natural language, many forms are lexically ambiguous (eg "form" is noun or verb). Lexical disambiguations are designed to choose the right solution(s) whenever possible. Various parameters are relevant to evaluate methods of lexical disambiguation and to discuss research about new methods: size of tagset, precision of results, recall, maintainability of disambiguators, predictability of results, expressive power of input and output forms. We will discuss and exemplify these parameters.
Thursday, August 27, 1998 20.00 - 21.00	Wilfrid Hodges	"Compositionality"	"Compositionality" has become a catch-all label for a range of questions about the proper form of a semantic theory. These questions are lagerly indipendent of each other, and they range from the deeper aims of a semantic theory to its surface syntax. Might it help to do a little mathematical deconstruting of the notion?