12th International Workshop on Termination (WST 2012) : WST 2012, February 19–23, 2012, Obergurgl, Austria / ed. by Georg Moser

This volume contains the proceedings of the 12th International Workshop on Termination (WST 2012), to be held February 19–23, 2012 in Obergurgl, Austria. The goal of the Workshop on Termination is to be a venue for presentation and discussion of all topics in and around termination. In this way, the workshop tries to bridge the gaps between different communities interested and active in research in and around termination. The 12th International Workshop on Termination in Obergurgl continues the successful workshops held in St. Andrews (1993), La Bresse (1995), Ede (1997), Dagstuhl (1999), Utrecht (2001), Valencia (2003), Aachen (2004), Seattle (2006), Paris (2007), Leipzig (2009), and Edinburgh (2010). The 12th International Workshop on Termination did welcome contributions on all aspects of termination and complexity analysis. Contributions from the imperative, constraint, functional, and logic programming communities, and papers investigating applications of complexity or termination (for example in program transformation or theorem proving) were particularly welcome. We did receive 18 submissions which all were accepted. Each paper was assigned two reviewers. In addition to these 18 contributed talks, WST 2012, hosts three invited talks by Alexander Krauss, Martin Hofmann, and Fausto Spoto

Robust Grammatical Analysis for Spoken Dialogue Systems

We argue that grammatical analysis is a viable alternative to concept spotting for processing spoken input in a practical spoken dialogue system. We discuss the structure of the grammar, and a model for robust parsing which combines linguistic sources of information and statistical sources of information. We discuss test results suggesting that grammatical processing allows fast and accurate processing of spoken input.Comment: Accepted for JNL

Using an ontology for guiding natural language interaction with knowledge based systems

Des dels anys 80, els sistemes basats en el coneixement, programes que utilitzen una gran quantitat de informació per modelar situacions i resoldre problemes, han adquirit gran importància en el camp industrial, financer i científic. La complexitat d'aquests sistemes fa que el seu ús presenti més dificultats que altres aplicacions informàtiques. La comunicació entre els sistemes basats en el coneixement i l'usuari presenta, doncs, nous reptes. Tot i que el llenguate natural es especialment apropiat per comunicar-se amb aquests sistemes, són pocs els que incorporen interfícies en llenguatge natural. Els motius principals són els problemes d'eficiència que presenta el processament del llenguatge natural i l'elevat cost de desenvolupar les bases de coneixement (conceptual i lingüístic) necessàries per a cada aplicació. L'objectiu d'aquesta tesi és millorar la comunicació en llenguatge natural amb els sistemes basats en el coneixement. Aquesta recerca s'ha centrat en el disseny d'una representació reutilitzable dels diferents tipus de coneixement involucrats en aquesta comunicació, que permetir de generar de forma automàtica la interfície més adequada per a cada aplicació. S'ha desenvolupat un sistema, GISE (Generador de Interfaces a Sistemas Expertos), que genera interfícies en llenguatge natural per diferents tipus d'aplicacions. Aquest sistema adapta automàticament les bases de coneixement lingüístic generals als requeriments d'una aplicació concreta, obtenint la gramàtica més apropiada. El disseny del sistema està basat en una representació reutilitzable i modular dels diferents tipus de coneixement necessaris en la comunicació en llenguatge natural. Aquesta informació consisteix en els conceptes de l'aplicació, les tasques de comunicació, el coneixement lingüístic i les relacions generals entre el coneixement conceptual i la seva realització lingüística. Tres bases de coneixement s'han dissenyat per representar aquesta informació: la ontologia conceptual, la ontologia lingüística i un conjunt de relges de producció. El coneixement conceptual s'ha representat en la ontologia conceptual. Aquest coneixement inclou aspectes sobre el domini i la funcionalitat. Tota la informació necessària per modelar l'aplicació i tots els possibles actes de comunicació estan representats en la ontologia conceptual. La complexitat dels sistemes basats en el coneixement fa necessària una representació formal i explícita de la seva funcionalitat i domini.El coneixement lingüístic general necessari per expressar en llenguatge natural les possibles tasques del sistema es representen en la ontologia lingüística.La informació que permet relacionar el coneixement lingüístic general a una aplicació concreta per tal d'obtenir la gramàtica més adequada es representada mitjançant un conjunt de regles de producció.L'organització modular dels diferents tipus de coneixement que intervenen en la comunicació facilita l'adaptació del sistema a diferents tipus d'aplicacions i usuaris.Les gramàtiques generades pel sistema GISE utilitzen un llenguatge alhora ric i precís, adaptat a l'aplicació. La interfície del sistema incorpora un sistema de finestres que guia a l'usuari a introduir les opcions en llenguatge natural que el sistema reconeix.GISE s'ha aplicat a diferents sistemes: a SIREDOJ, un sistema expert en lleis i a un sistema que dóna informació sobre trens.Since the 1980's, knowledge based systems (KBSs), programs that use knowledge to model situations and solve problems, have spread throughout industry, finance and science. Human communication with these systems deals with complex concepts and relationships that are not present in other software applications. Allthough the natural language (NL) is especially appropriate for expressing these concepts, there are not many KBSs incorporating NL interfaces. The main reasons for this are problems of efficiency in NLI performance, lack of adequacy to the communication needs of the applications and the high cost of developing and maintaining them.The aim of this thesis is to study how the communication process and engineering features can be improved in NL interaction with KBSs. This study has been focused on the efficient and reusable representation of the knowledge involved in NL communication with KBSs. GISE (Generador de Interfaces a Sistemas Expertos), a system supporting NL communication with KBSs has been developed. This system adapts the general linguistic resources to application requirements in order to automatically obtain application-restricted grammars. The main issue of the system design is a separate and reusable representation of all types of knowledge involved in communication with KBSs. This knowledge consists of the application knowledge appearing in the communication, the tasks of communication, the linguistic knowledge supporting their expression and the general relationships between conceptual knowledge and its linguistic realization. Three general bases were designed to represent all this knowledge : the Conceptual Ontology (CO), the Linguistic Ontology (LO) and a set of control rules.Conceptual knowledge is represented in the CO. This conceptual knowledge includes domain and functionality issues. All knowledge required to model the applications as well as the description of all possible communication acts is provided in the CO. The CO is the skeleton for anchoring the domain and the functionality of the applications. The complexity of KBS performance makes a formal and explicit representation of their domain and functionality necessary. The general linguistic knowledge needed to cover the expression in NL of the tasks the system performs is represented by means of the LO and a set containing all possible realizations of the application terms. The LO is domain and application independent. The control information to relate the general linguistic knowledge to conceptual application knowledge in order to generate the application-restricted grammars is represented by a set of production rules. The modular organization of the relevant knowledge into separate data structures provides great flexibility for adapting the system to different types of applications and users.The grammars generated by GISE use expressive and precise language tuned to the application and adapted to the evolution of the communicative process. A menu-system to guide the user in introducing the NL is integrated into the GISE interface. GISE has been applied to a couple of applications: SIREDOJ, an ES in law and a railway communication system

Exact Recursive Probabilistic Programming

Recursive calls over recursive data are widely useful for generating probability distributions, and probabilistic programming allows computations over these distributions to be expressed in a modular and intuitive way. Exact inference is also useful, but unfortunately, existing probabilistic programming languages do not perform exact inference on recursive calls over recursive data, forcing programmers to code many applications manually. We introduce a probabilistic language in which a wide variety of recursion can be expressed naturally, and inference carried out exactly. For instance, probabilistic pushdown automata and their generalizations are easy to express, and polynomial-time parsing algorithms for them are derived automatically. We eliminate recursive data types using program transformations related to defunctionalization and refunctionalization. These transformations are assured correct by a linear type system, and a successful choice of transformations, if there is one, is guaranteed to be found by a greedy algorithm

Density Matrices with Metric for Derivational Ambiguity

Recent work on vector-based compositional natural language semantics has proposed the use of density matrices to model lexical ambiguity and (graded) entailment (e.g. Piedeleu et al 2015, Bankova et al 2019, Sadrzadeh et al 2018). Ambiguous word meanings, in this work, are represented as mixed states, and the compositional interpretation of phrases out of their constituent parts takes the form of a strongly monoidal functor sending the derivational morphisms of a pregroup syntax to linear maps in FdHilb. Our aims in this paper are threefold. Firstly, we replace the pregroup front end by a Lambek categorial grammar with directional implications expressing a word's selectional requirements. By the Curry-Howard correspondence, the derivations of the grammar's type logic are associated with terms of the (ordered) linear lambda calculus; these terms can be read as programs for compositional meaning assembly with density matrices as the target semantic spaces. Secondly, we extend on the existing literature and introduce a symmetric, nondegenerate bilinear form called a "metric" that defines a canonical isomorphism between a vector space and its dual, allowing us to keep a distinction between left and right implication. Thirdly, we use this metric to define density matrix spaces in a directional form, modeling the ubiquitous derivational ambiguity of natural language syntax, and show how this alows an integrated treatment of lexical and derivational forms of ambiguity controlled at the level of the interpretation.Comment: 24 pages, 10 figures. SemSpace 2019, to appear in J. of Applied Logic