# Courses' slots:

# Week one 9:00 - 10:30

## Language and Logic foundational course:

The Logic of Sense and Reference.

Teacher
Abstract: Most of our logics identify semantic values that should not be identified. As a result they come with problems such as prediction of logical omniscience. These can be evaded by distinguishing between an expression's sense and its reference, in Frege's way. This course studies logics in which such a distinction is made and in which even logically equivalent sentences can be kept apart and be assigned different meanings. It will also consider applications of such logics. Church's Logic of Sense and Denotation is a prime example of the kind of logic intended here, but there are now many more. After an overview of some of the proposals that have been made, the course will focus upon the classical theory of types and it will be explained how a natural generalization of Henkin's general models for this logic leads to structures with the desired characteristic: senses as well as referents being available as semantic values. It will turn out that the system thus obtained has many nice logical properties, completeness with respect to a very straightforward Gentzen calculus being one of them. It will also be shown how in a set-up where expressions come with senses the usual ingredients of possible worlds semantics can be constructed. The course will emphasize ideas rather than logical technique and should be accessible to natural language semanticists who are interested in getting rid of a foundational difficulty of their discipline.

## Logic and Computation foundational course:

Ontology Modelling Languages.

Teachers
Abstract:
Ontologies are currently becoming the major paradigm for knowledge representation and reasoning. Their success is driven by the Semantic Web effort, but there is also considerable use outside the Web context, e.g. in information integration or life sciences. In this course, we will present an in-depth treatment of the ontology representation languages RDF and OWL, which are recommended standards by the World Wide Web consortium. We will thoroughly examine their logical underpinnings and discuss current research topics and applications. The outline of the course will be as follows:

(1) RDF and RDF Schema

(2) OWL and Description Logics

(3) Tableaux algorithms for OWL

(4) Query languages

(5) Applications.

## Logic and Computation introductory course:

Non-deterministic Multi-valued Logics.

Teachers
- Arnon Avron ()
- Beata Konikowska ()

Non-deterministic multi-valued logics is a recent natural generalization of ordinary multi-valued logics which has been inspired by the idea of non-deterministic computation from Computer Science. In this course we introduce the basic concepts and results related to both ordinary multi-valued logics and their non-deterministic generalizations. We then demonstrate the usefulness of the non-deterministic approach by providing semantics for thousands of non-classical logics, in particular paraconsistent logics, fuzzy logics and other logics for reasoning under uncertainty. Another application which will be described is the construction and characterization of analytic proof systems for a variety of logics, including classical and intuitionistic logics (the relevant proof theoretical concepts will be described in the course). Another application which will be dealt with in the course using the tool of non-deterministic logics is a complete mathematical solution to the famous philosophical "Tonk" problem. The course assumes only a basic background in formal logic.

## Language and Computation introductory course:

The mental lexicon, blueprint of the dictionaries of tomorrow: linguistic, computational and psychological aspects of a highly valuable resource

Teacher
- Michael Zock ()

Keywords: electronic dictionaries, mental lexicon, word access, organisation of the lexicon, index creation for navigational purposes

Abstract:
Whenever we read a book, write a letter or launch a query on google, we always use words, the shorthand labels of concepts. Words are building blocks which, if properly combined, allow us to express complex thoughts. No doubt, words are important. The question is how are they learned or stored, how are words represented, organized and accessed? The answer to these questions will be the topic of course.

After addressing some fundamental questions (what are words? Are they stored as holistc entities or in a modular form?, etc.), we will discuss various types of dictionaries (paper, electronic and mental), their making (by hand, semi automatically) and use (on-line, off-line). We will then introduce some of the techniques currently used in computational lexicography. Finally we will take a look at some of the findings in psychology and neurolinguistics and consider their possible relevance for dictionary builders (How should words be organized and indexed in order to allow for quick and intuitive access?).

With the advent of corpora and computational tools (computers and programs) many things have changed, so has our knowledge concerning the mental lexicon. Dictionaries are huge storehouses of words with various kinds of information associated with each of them. One might think, the larger the better. Yet, dictionaries, complete as they may be, are of limited use, if we cannot access the information they contain. Organization and indexing are critical factors for which lexicographers may get inspired by looking at the psychologists' work.

We will heavily draw on the following sources for this course (see also the reference section): Atkins & Rundell (2008) and Fontenelle (2008) for 'computational lexicography' and Aitchison (2003), Bonin (2007) for work on the 'mental lexicon'.

## Language and Computation advanced course:

An introduction to minimalist grammars.

Teachers
- Gregory Kobele ()
- Jens Michaelis ()

Course material: main.pdf gaertner_michaelis-mtsat10-esslli07.pdf Kobele06-2.pdf michaelis-lacl01-esslli-09.pdf minimalism-lacl98-esslli09.pdf

Abstract:Research in the tradition of Chomsky's minimalist program is often inaccessible to non-minimalists, partly because of the highly intuitive level at which much of the work in this tradition is conducted. This course will show how major components of recent Chomskian syntax can be expressed in formal grammars inspired by Stabler's "minimalist grammar" (MG). Many MG variants have been rigorously related to MC-TAGs and other well-understood formalisms, so that now a wide range of Chomskian proposals can be understood and assessed by formally minded linguists from every linguistic tradition. Considering especially recent (empirically consequential) proposals about locality, copying operations, adjunction, and interfaces (phonetic, morphological, semantic), this formal treatment sometimes reveals surprising aspects of those proposals---in particular when being depicted against the "classical" background of parsing complexity and generative capacity---that have been obscured in the informal literature.

## Language and Logic introductory course:

Introduction to Abstract Categorial Grammars: Foundations and main properties.

Teachers
- Philippe de Groote ()
- Sylvain Salvati ()

The abstract categorial grammar (ACG) introduced by de Groote (2001) derives from the categorial and type-logical tradition, and is based on principles that may be traced back to both Curry and Lambek. This course will focus on the main concepts underlying the ACG. We will first motivate the formalism by showing how it derives from the categorial grammar tradition. We will then illustrate the expressive power of the ACG by showing how several grammatical formalisms may be encoded as ACGs. We will review the fundamental properties (membership, universal membership, emptyness...), and establish a formal relation between ACG and linear logic. Finally, we will review possible extensions of the formalism, and discuss their properties.

# Week one 11:00 - 12:30

## Language and Computation foundational course:

The Foundations of Statistics: A Simulation-Based Approach.

Teacher
Abstract:
I will develop the statistical theory underlying hypothesis testing from first principles, using elementary probability theory and Monte Carlo simulations. I will use the programming language R (http://cran.r-project.org/). In addition, we will discuss issues such as data visualization and data management for realistic datasets.

We will use a newer version of this freely available online textbook: http://www.ling.uni-potsdam.de/~vasishth/SFLS.html

Day 1: Basics of R

Day 2: t-tests and confidence intervals

Day 3: statistical power, Type I and Type II errors

Day 4: linear models and their connection with t-tests

Day 5: multiple regression and mixed-effects models

This course will be useful for anyone doing any kind of quantitative research. Students typically learn cookbook statistics, an approach which often leads to significant misunderstandings regarding hypothesis testing. This course has been developed to help correct such problems.

Each lecture will be accompanied by practical exercises to be completed after class; solutions will be provided the following day.

## Logic and Computation introductory course:

Temporal logics for specification and verification.

Teacher
Course material: Goranko-ESSLLI2009CourseNotes.pdf

Abstract:
The course will cover the following topics:

I. Transition systems and computations. Important properties of
transition systems: safety, eventualities, fairness,
reachability. Formal specification and verification of
properties of transition systems. Temporal logics as languages
for specification.

II. Linear and branching time models of computations.

Linear time temporal logics. Expressing properties of
computations in transition systems using LTL.

Satisfiability of LTL specifications. Verification of LTL
specifications by model checking.
Branching-time temporal logics. Expressing properties of
computations in transition systems using CTL and CTL*.

Satisfiability of CTL specifications. Verification of CTL
specifications by model checking.

III. Buchi automata on infinite words and trees. Automata
recognizing models of temporal formulae.

Automata-based methods for satisfiability and model checking of
linear and branching time temporal formulae.

IV. Tableau-based methods for testing satisfiability and
model-checking of linear and branching time temporal formulae.

V. Optional, subject to time availability: Introduction to modal
mu-calculus. Model checking of mu-calculus formulae.

## Logic and Computation introductory course:

Logics of individual and collective intentionality.

Teachers
Abstract:
This course presents basic concepts about individual and
collective intentionality which have been studied in the
multi-agent domain and in the philosophical domain. We will
discuss the most important logical theories developed in the
last two decades to formalize individual and collective
attitudes such as knowledge, belief, preference, intention,
group belief (i.e. distributed belief, common belief, collective
acceptance), collective intention. The course is also devoted to
clarify the philosophical foundations of such concepts. In the
first part of the course we will focus on individual
attitudes. In the second part of the course we will focus on
collective attitudes.

COURSE OUTLINE.

KNOWLEDGE AND BELIEF (Day 1):

- Kripke models, logics S5, KD45;

- Omniscience problem;

- Link between belief and knowledge.

GOALS AND INTENTIONS (Day 2):

- Bratman's theory of intention;

- Cohen & Levesque's logic of intention;

- Other BDI approaches (Rao & Georgeff, Meyer & Van der
Hoek, Wooldridge);

- Intention, intentional actions and attempts.

DYNAMICS OF BELIEFS, GOALS AND PREFERENCES (Day 3):
- Dynamic Epistemic Logic (DEL);

- Belief revision (AGM approach);

- Integrations of DEL and AGM;

- Logics of goal and preference change (Liu, Shapiro et al.).

GROUP BELIEF (Day 4):

- Philosophical theories of group belief (Lewis, Tuomela, Gilbert);

- Logics of distributed, mutual and common belief;

- The logic of collective acceptance.

GROUP INTENTION (Day 5):

- Philosophical theories of collective intention (Bratman, Tuomela);

- Logical theories of collective intention (Cohen et al., Grosz
& Kraus, Dunin-Keplicz & Verbrugge).

PREREQUISITES.
We assume basic background knowledge of modal logic.

## Language and Logic introductory course:

Quotation and the semantics of speech reports.

Teacher
- Emar Maier ()

In every language we can say things about the world, but also
about the language itself. In both natural and formal languages
we find quotational devices dedicated to this task of turning a
language on itself. In this course I give an introduction to the
semantics of quotation, focusing on its use in natural language
speech reporting. Entering more recent debates we'll explore in
some detail the semantics of mixed quotation, and 'monstrous'
perspectival shifts.

The starting point is the basic opposition between use and
mention and the classic analyses of quotation (Quine, Tarski,
Geach and Davidson). In the second lecture I apply these insights
to the semantics of natural language speech reporting where we
find an apparent parallel to our basic opposition in the
distinction between indirect and direct discourse. I'll explore
the standard reductions of direct discourse to mention, and
indirect discourse to use (under an intensional operator in
Kaplan's (1989) 'Logic of Demonstratives'). In the third lecture
we'll consider the pros and cons of these standard approaches, in
particular the recent challenges to Kaplan posed by shifted
indexicals and Schlenker's (2003) analysis in terms of
'monsters'.

The most interesting type of speech report however is mixed
quotation, which combines aspects of direct discourse/mention and
indirect discourse/use. In the final two lectures we compare the
main views in the ongoing debate about the semantics of this
construction: Cappelen and Lepore (1997), Recanati (2001), Potts
(2007), and Geurts and Maier (2005). I close by considering the
possibility of extending the semantics of mixed quotation to
account for the indexical shift phenomena problematic for the
classic Kaplanian framework.

## Language and Logic advanced course:

How to do things with words: Speech Acts in Linguistics, Philosophy and Computation.

Teachers
Abstract:
Speech acts have been discovered in philosophy as acts that can
be done with words or moves in a language game. They still pose
a challenge to semantic theory where, typically, declarative
sentences are analysed as denoting propositions. The two views
of sentences as containers of information, and as moves in
social interaction, can not easily be reconciled.

Grammar and speech act level are not completely
disconnected. Practically all languages distinguish between
three sentence modes, declarative, interrogative, imperative,
which are prototypically tied to the respective speech acts. But
many more aspects of grammar refer to language's function in
social interaction: The use of subjunctive can serve to
distinguish reported speech acts from executed speech
acts. Particles, discourse adverbs and NPIs can serve as speech
act markers. Examples abound, consider German wohl which turns
questions into self-directed questions: Wer bringt Kaffee mit?
"who will bring coffee?" (real question) Wer bringt wohl
Kaffee mit? "who will wohl bring coffee?" (speaker asks
herself) Doch/denn distinguish verb-initial exclamatives from
yes/no questions: Hat er denn einen Hund mitgebracht? "has he
brought along a dog?" Hat er doch einen Hund mitgebracht!
"And what he did was bring a DOG along!" Intensifiers like
English so can be used to emphasize properties ("He is so
tall.") but arguably (Potts) also (preconditions of) speech
acts ("He is so next in line.").

Historical ties Research on grammaticalization proves that
indirect directive speech acts grammaticalize into grammarical
markers of imperative sentence mood. Strikingly, languages
exhibit exactly those grammaticalization paths that would be
predicted by Searle's theory of indirect speech acts. While this
parallel is satisfactory from a theoretical perspective, its
consequences are largely unexplored. Are similar
grammaticalization patterns known for other indirect speech
acts? Other sentence modes? Why is it that grammars limit
themselves to three sentence modes while major speech act
classifications rest on at least five-six major groups, which
subdivide into many more specific kinds of acts?

Analysis of speech acts
Formal theories of speech acts exist (e.g. SDRT,
Asher/Lascarides, but also philosophical approaches ranging from
Stalnaker/Lewis to Searle/Vanderveken), but are usually phrased
as orthogonal to, and disconnected from truth conditional
semantics of the clause. However, there are many words that have
a meaning both in semantics and at speech act level; consider
quantification into speech acts, cookie conditionals ("if
you're hungry, there are cookies on the table") and
more. Can such cross-domain phenomena be captured in a way that
makes the ties between the two levels maximally transparent?
Related to this is the question whether there is any way to
delimit the number of speech acts, and to come up with clear
criteria to identify and distinguish them.

Speech acts and automatic language processing

Finally, applications in language processing are often based on
a scenario of speaker-machine interaction which involves more
than a simple exchange of propositional content. Such
applications often rest on simple, task-driven models of
"doing things with words". Is there anything that
formal semanticists can learn from such theories that have been
tested against real communication? Can semanticists contribute
something to this type of models?

## Language and Computation introductory course:

Grammaticality Judgements as Linguistic Evidence.

Teacher
- Brian Murphy ()

The current use of grammaticality judgements to evaluate the "goodness" of linguistic utterances is controversial (see e.g. Schutze; Wasow & Arnold). The more systematic approaches advocated by Bard and others remain a minority practise. Now, a new consensus is emerging (see e.g. Murphy; Featherston; Weskott & Fanselow), that i) theories of grammar may be investigated independently of models of acceptability judgements and ii) various judgement scales access a single cognitive competence. The course will begin with a quick review of theoretical views of grammaticality. The main part of the course will then introduce concrete methodological guidelines for gathering materials, composing instructions, presenting utterances, choosing among different judgement scales, and selecting appropriate statistical tests for analysis. Publicly available software will be introduced, with an emphasis on web-based testing. Acceptability judgements will be situated relative to other methodologies, including ERP analysis, timed reading and corpus analysis. The course will assume foundational knowledge of linguistics. particulars

# Week one 14:00 - 15:30

## Language and Logic advanced course:

Plurality and distributivity across language(s) and logic(s).

Teachers
- Eytan Zweig ()
- George Tsoulas ()

Keywords: plurality, distributivity

Abstract:This course offers an in-depth survey of the state of the art in the research on plurality and distributivity. While logic treats distributivity as a straightforward logical property of quantifiers and predicates, natural languages present a picture both more subtle and complex. Different languages exhibit an array of strategies for the expression of distributivity and many different constraints on what can acquire a distributive interpretation in which contexts. We present a picture of the crosslinguistic variation in the expression of distributivity drawing data from languages including English, French, German, Greek, Korean, and Japanese. Attempting synthesis of insights from plural logics and from the linguistic semantics of distributivity, we will examine what is necessary for a plural logic system that will capture the nuances expressed across natural languages. The course is addressed to students with a solid grasp of basic semantics including generalised quantifier theory and basic notions of boolean algebra.

## Logic and Computation advanced course:

Game semantics and its applications.

Teacher
Abstract: In recent years game semantics has emerged as a robust paradigm for giving semantics to a variety of logical systems and programming languages. Its precision in modelling has subsequently led to original applications in program analysis and model checking. This course is meant to provide a self-contained introduction to the field along with a survey of ongoing applied work.

## Logic and Computation workshop:

Logical Methods for Social Concepts.

Organizers
Course material: AquilkhanBanerjee.pdf BalbianiDitmarschSeban.pdf Broersen.pdf DegremontKurzen.pdf Dimitri.pdf EckertHerzberg.pdf GenotJacot.pdf GhoshVelazquez.pdf GierasimczukKurzenVelazquez.pdf HakliNegri.pdf LonginNguyen.pdf RousselCholvy.pdf Tuomela.pdf

Abstract:
Both computer science and the social sciences are interested in
concepts such as power, cooperation, responsibility, delegation,
trust, reputation, convention, agreement, commitment, etc. The
aim of the workshop is to study whether logical approaches
developed in the multi-agent system (MAS) domain are adequate to
express them in an accurate way. In particular, are existing
logical approaches sufficiently expressive to capture the main
features of these social concepts? Are the basic assumptions in
the existing logics for MAS too strong to capture the
fundamental aspects of social phenomena? Are some concepts
relevant for social theory missing in these logics?

We encourage not only works focused on the technical aspects of
logics for multi-agent system, but also works including
multidisciplinary aspects from social sciences (e.g. economics,
sociology, social philosophy) and providing a critical analysis
of the existing logical frameworks for the specification of
social concepts. Indeed, the workshop is intended to bring
together logicians and social theorists in order to provide a
better understanding of the potentialities and limitations of
logical methods for the analysis of social reality.

The following are some examples of topics that are relevant for the workshop.

- Logics of individual and collective powers
- Logical approaches to game theory
- Public announcements logics and logics of communication
- Logical approaches to trust and reputation
- Logical approaches to organizational concepts (e.g. roles, responsibility, delegation)
- Logics of social commitment and collective attitudes
(e.g. common belief and common knowledge, collective acceptance,
joint intentions)

- Logics for mechanism design

## Language and Logic introductory course:

Focus, Focus Interpretation, and Focus Sensitivity.

Teachers
- Malte Zimmermann ()
- Daniel Hole ()

The course offers an overview of standard implementations of the meaning of focus and the structural and semantic behaviour of focus-sensitive elements (quantificational adverbs, focus particles). The course integrates the discussion of empirical phenomena with recent semantic (and syntactic) theories. 1: Introduction: Focus phenomena and Alternative Semantics (Rooth 1985, 1992, Schwarzschild 1999) 2: Structured Propositions and Focus Movement (von Stechow 1991, Rooth 1996, Krifka 2006) 3: Semantic effects of explicit focus marking: Contrast, exhaustivity in clefts and Hungarian focus constructions (Horn 1981, Kiss 1998, Wedgwood 2003, Horvath 2008) 4: The semantics of focus-sensitive particles ('only', 'also', 'even') and quantificational adverbs (KÃƒÂ¶nig 1991, Rooth 1996, Beaver & Clark 2004, Beaver, to appear) 5: Extensions and case studies: (i.) Postposed additive particles ('AUCH', 'too') as topic-sensitive expressions (Krifka 1999); (ii.) Multiple association with focus (Krifka 1992, Wagner 2007); (iii.) Particle proliferation in Southeast Asian and Dutch (Barbiers, to appear, Hole 2008).

## Logic and Computation advanced course:

Reasoning in complex theories and applications.

Teacher
Course material: sofronie-lecture-esslli-09.pdf

Abstract:
The goal of this course is to give a comprehensive, in-depth
perspective on recent advances in the field of reasoning in
complex logical theories, and to present the applications of
these results in mathematics, formal verification and knowledge
representation.

We will start by explaining the importance of logical
formalization in various areas (mathematics, verification,
knowledge representation, AI). We will point out the
limitations of the logic formalization, as well as the necessity
of developing decision procedures. We will argue, using various
examples, that concrete problems often are quite heterogeneous
in nature, such that combinations of reasoning tools
(resp. decision procedures) for various theories might be needed
in the same application. We will introduce the necessary
theoretical concepts and give a survey of decidable and
tractable logical theories. We will then present recent
achievements which address the main problems which occur in this
context, starting from SAT checking in classical logic and
continuing with tests of satisfiability modulo a theory, modular
reasoning in combinations of theories (under various conditions
on their shared signatures) and hierarchical reasoning in theory
extensions. We will present the main ideas which appeared in the
literature from a unifying perspective. We will illustrate the
problems and the solutions on examples from mathematics,
verification and knowledge representation.

## Language and Computation workshop:

Parsing with Categorial Grammars

Organizer
- Gerald Penn ()

Keywords: categorial grammar, parsing, semantic inference

Abstract:
Among computational linguists, there has been an enormous resurgence of interest recently in parsing with categorial grammars, both because of their extreme lexicalism and because of their well-defined connection to interpretable semantic terms. The recent work of Clarke, Curran and others on Combinatory Categorial Grammars, and of Moot, Baldridge and others on multimodal extensions of categorial grammar, in particular, has produced a collection of efficient and expressive parsing tools that have only just begun to make an impact on tasks such as the Pascal RTE challenge. As the CL community attempts to push the state of the art from mere syntactic annotation into parsers that actually allow for semantic inference, CG's position can only improve. At the same time, there is no shortage of variations on "categorial grammar," and there has not to date been a great deal of communication between the adherents of these various strands on their relative linguistic or semantical merits, nor on more technical concerns of algorithm design and numerical parametrization.

The aim of this workshop is to bring researchers in these various strands to share and assess their progress in the spirit of promoting categorial grammar's overall advancement. ESSLLI has a long and distinguished history of offering CG courses and workshops, most recently Glyn Morrill's course on Type-Logical Grammar (2007), but these have typically mixed lectures on connections to linguistic theory with more formal lectures on parsing and tractability within one strand of scholarship. The focus of this workshop, however, will be squarely on the formal / computational side, with the intention of representing work across all variations of categorial grammars.

# Week one 17:00 - 18:30

## Language and Logic advanced course:

Theoretical and Empirical Perspectives on Discourse.

Teacher
Abstract: This course will present an overview of current research on discourse both from a theoretical and empirical point of view. I will begin with the theoretical point of view, concentrating on Segmented Discourse Representation Theory (SDRT), which has made most explicit the ties between discourse semantics and more traditional linguistic fields of pragmatics and semantics. I will also compare RST, DLTag and other theories to SDRT. I then will detail the empirical stumbling block for all of these theories, which is the scaling up to real world, domain independent texts. I will review empirical approaches to discourse parsing in an attempt to address this empirical problem. I will discuss corpus construction and learning methods, leaning on the results of the Penn Discourse Tree Bank, Graph Bank, and the SDRT annotation projects DISCOR and ANNODIS.

## Logic and Computation workshop:

Structures and Deduction 2009.

Organizers
- Michel Parigot ()
- Lutz Strassburger ()

Course material: structures_deduction.pdf

Abstract:
The topic of this workshop is the application of algebraic,
geometric, and combinatorial methods in proof theory. In
traditional proof theory, research is focussed on syntax, but in
recent years many researchers have proposed approaches to avoid
"syntactic bureaucracy" in the presentation of proofs. Examples
are proof nets, atomic flows, new deductive systems based on
deep inference, and new algebraic semantics for proofs. These
efforts have also led to new methods of proof normalisation and
new results in proof complexity.

Thus the workshop is relevant to a wide range of people. The
list of topics includes among others: algebraic semantics of
proofs, game semantics, proof nets, deep inference, tableaux
systems, category theory, deduction modulo, cut elimination,
complexity theory, computational interpretation of proofs, etc.

The goal of the workshop is twofold: first, to bring together
researchers from various fields who share the interest in
reducing the dependency of logic from low-level syntax, and
second, to provide an opportunity for PhD students and
researchers to present and discuss their work with colleagues
who work in the broad subject areas that are represented at
ESSLLI.

The workshop is intended to be a sequel of the ICALP-workshop
SD05 in Lisbon 2005 .

## Language and Logic introductory course:

Logicality and Invariance.

Teacher
- Denis Bonnay ()

Course material: bonnaylogicalityandinvariance.pdf syllabuslogicalityandinvariance.pdf vanbenthembonnaymodallogicinvariance.pdf

Abstract:
When designing a logical system, one has to start by distinguishing between logical expressions, which are the proper objects under study and whose interpretations remain fixed across models, and non-logical expressions, whose interpretations are permitted to vary from one model to the other. In particular, this distinction is crucial for the definition of logical truth as truth in all models. But are there principled ways to draw the line between logical and non-logical expressions? Consider any logical system, what is its natural repertoire of logical operations?

The aim of the course will be to review the semantic answers to these questions and to evaluate their consequences with respect to general questions in logic (such as functional completeness results), in linguistics (such as the semantic nature of `functional' or `grammatical' expressions) and in the philosophy of the formal sciences (why is logic different from mathematics?).

I will present the standard approach in terms of permutation invariance, which is generally credited to Tarski, and then introduce a generalized framework for the analysis of various invariance criteria. In particular, I will show how bisimulation invariance and invariance under potential isomorphism come out as natural notions of invariance for modal logic and first-order logic.

Course materials will be made available on my webpage:
http://lumiere.ens.fr/~dbonnay/

## Logic and Computation introductory course:

Games, Action and Social Software.

Teachers
Abstract:
Social software is a term coined by Rohit Parikh for the emerging discipline that investigates the logical, computational and strategic aspects of social mechanisms. The course will give an overview of choice topics in this area, and draw connections with game theory, action logic, epistemic logic, and social choice theory.

Point of departure will be a collection of Discourses on Games, Action and Social Software that is due to appear with Amsterdam University Press, in the Texts in Logic and Games series.

The level of the course will be the level of the discourses in the book, or slightly more advanced.

Each course lecture will be based on one or two of the discourse chapters from the book.

## Language and Computation advanced course:

Computational Psycholinguistics.

Teacher
- Roger Levy ()

Over the last two decades, computational linguistics has been revolutionized by increases in computing power, large linguistic datasets, and a paradigm shift toward the view that language processing by computers is best approached through the tools of statistical inference. During roughly the same time frame, there have been similar theoretical developments in cognitive psychology towards a view of major aspects of human cognition as instances of rational statistical inference, exemplified by work such as Anderson (1990) and Tenenbaum & Griffiths (2001). Developments in these two fields have set the stage for renewed interest in computational approaches to human language processing. Correspondingly, this course covers some of the most exciting developments in computational psycholinguistics over the past decade. The course focuses on probabilistic knowledge and memory in language processing, covering models, algorithms, and key empirical results in the literature.

## Language and Logic workshop:

Vagueness in Communication.

Organizers
Course material: vic09-alxatib-pelletier.pdf vic09-daniel-lassiter.pdf vic09-ewan-klein.pdf vic09-gottfried-vosgerau.pdf vic09-harald-bastiaanse.pdf vic09-lavi-wolf.pdf vic09-pablo-cobreros.pdf vic09-paul-egre.pdf vic09-stephanie-solt.pdf vic09-zardini-sweeney.pdf

Abstract:
Although vagueness has long since been an important topic in
philosophy, logic and linguistics, some recent advances have made the
functions of vagueness in natural language communication an exciting
and timely research area. This renewed interest has a distinct
cross-disciplinary character and has spawned many new research
questions. While the classical instruments of dealing with vagueness
-- like multi-valued logics, truth value gaps or gluts, or
supervaluations -- have not been significantly extended, new
approaches investigate questions like context-sensitivtiy of vagueness
(Kyburg & Moreau 2000), the sharpening of vague predicates in context
(Barker 2002), and the modeling of precision levels with expressions
like 'roughly' or 'like' (Kennedy 2007). Within the study of
comparatives and degree modification, moreover, researchers are now
exploring cross-linguistic aspects of vagueness (Beck et al 2004). On
a more fundamental level, the question why there is vagueness to begin
with, what role vagueness serves in human communication, has been
addressed. For example, it has been argued that vagueness is an
epiphenomenon of the impossibility of complete shared knowledge about
the extension of many terms (e.g. Williamson 1994), hence a
consequence of the cognitive limitations of humans. It has been shown
why this does not affect the utility of these terms in communication
(Parikh 1994). Game-theoretic methods have been employed that show
that being vague or imprecise can be beneficial for communication even
if the speaker could truthfully use more precise terms (de Jaegher
2003). Furthermore, the important role of vagueness became evident in
a number of empirical domains beyond obvious examples such as the
language of diplomacy -- for example, in geographical terms (e.g.
Bennett 2008) or in the description of measures of economy (Qizilbash
2005). There are also initial experimental investigations into the
ways how speakers interpret vague terms (e.g., Bonini e.a. 1999).

The workshop aims to bring together researchers whose work contributes
to the broad inter-disciplinary line of inquiry outlined here. In
particular, we welcome:

* papers that broaden the empirical base for the study of
vagueness, be it linguistic or otherwise;
* papers offering a synthesis of theories from different disciplines; and
* papers addressing the pragmatics of vagueness.

The workshop aims to provide a forum for researchers (including
advanced PhD students) to present and discuss their work with
colleagues and researchers who work in the broad subject of the
disciplines relevant for vagueness in communication, as represented in
ESSLLI.