Feature Unification in TAG Derivation Trees

The derivation trees of a tree adjoining grammar provide a first insight into the sentence semantics, and are thus prime targets for generation systems. We define a formalism, feature-based regular tree grammars, and a translation from feature based tree adjoining grammars into this new formalism. The translation preserves the derivation structures of the original grammar, and accounts for feature unification.Comment: 12 pages, 4 figures In TAG+9, Ninth International Workshop on Tree Adjoining Grammars and Related Formalisms, 200

Algebraic Effects and Handlers in Natural Language Interpretation

International audiencePhenomena on the syntax-semantics interface of natural languages have been observed to have links with programming language semantics, namely computa- tional effects and evaluation order. We explore this connection to be able to profit from recent development in the study of effects. We propose adopting algebraic effects and handlers as tools for facilitating a uniform and integrated treatment of different non-compositional phenomena on the syntax-semantics interface.In this paper, we give an exposition of the framework of algebraic effects and handlers with an eye towards its applicability in computational semantics. We then present some exemplary analyses in the framework: we study the interplay of anaphora and quantification by translating the continuation-based dynamic logic of de Groote into a more DRT-like theory and we propose a treatment of overt wh-movement which avoids higher-order types in the syntax

Un sens logique pour les graphes sémantiques

posterInternational audienceWe discuss the meaning of semantic graphs, in particular of those used in Meaning-Text Theory. We provide a precise, possibly underspecified, meaning to such graphs through a simple translation into a Minimal Recursion Semantics formula. This translation covers cases of multiple predications over several entities, higher order predication and modalities.Nous discutons du sens des graphes sémantiques, notamment de ceux utilisés en Théorie Sens-Texte. Nous leur donnons un sens précis, éventuellement sous-spécifié, grâce à une traduction simple vers une formule de Minimal Recursion Semantics qui couvre les cas de prédications multiples sur plusieurs entités, de prédication d'ordre supérieur et de modalités

An ACG View on G-TAG and Its g-Derivation

International audienceG-TAG is a Tree Adjoining Grammar (TAG) based formalism which was specifically designed for the task of text generation. Contrary to TAG, the derivation structure becomes primary, as pivot between the conceptual representation and the surface form. This is a shared feature with the encoding of TAG into Abstract Categorial Grammars. This paper propose to study G-TAG from an ACG perspective. We rely on the reversibility property of ACG that makes both parsing and generation fall within a common morphism inversion process. Doing so, we show how to overcome some limitations of G-TAG regarding predicative adjunction and how to propose alternative approaches to some phenomena

Using Regular Tree Grammars to enhance Sentence Realisation

International audienceFeature-based regular tree grammars (FRTG) can be used to generate the derivation trees of a feature-based tree adjoining grammar (FTAG). We make use of this fact to specify and implement both an FTAG-based sentence realiser and a benchmark generator for this realiser. We argue furthermore that the FRTG encoding enables us to improve on other proposals based on a grammar of TAG derivation trees in several ways. It preserves the compositional semantics that can be encoded in feature-based TAGs; it increases efficiency and restricts overgeneration; and it provides a uniform resource for generation, benchmark construction, and parsing

Grammaires phrastiques et discursives fondées sur les TAG : une approche de D-STAG avec les ACG

International audienceThis article presents a method to interface a sentential grammar and a discourse grammar without resorting to an intermediate processing step. The method is general enough to build discourse structures that are direct acyclic graphs (DAG) and not only trees. Our analysis is based on Discourse Synchronous TAG (D-STAG), a Tree-Adjoining Grammar (TAG)-based approach to discourse. We also use an encoding of TAG into Abstract Categorial Grammar (ACG). This encoding allows us to express a higher-order semantic interpretation that enables building DAG discourse structures on the one hand, and to smoothly integrate the sentential and the discourse grammar thanks to the modular capability of ACG. All the examples of the article have been implemented and may be run and tested with the appropriate software.Nous présentons une méthode pour articuler grammaire de phrase et grammaire de discours qui évite de recourir à une étape de traitement intermédiaire. Cette méthode est suffisamment générale pour construire des structures discursives qui ne soient pas des arbres mais des graphes orientés acycliques (DAG). Notre analyse s'appuie sur une approche de l'analyse discursive, Discourse Synchronous TAG (D-STAG), qui utilise les Grammaires d'Arbres Adjoint (TAG). Nous utilisons pour ce faire un encodage des TAG dans les Grammaires Catégorielles Abstraites (ACG). Cet encodage permet d'une part d'utiliser l'ordre supérieur pour l'interprétation sémantique afin de construire des structures qui soient des DAG et non des arbres, et d'autre part d'utiliser les propriétés de composition d'ACG pour réaliser naturellement l'interface entre grammaire phrastique et grammaire discursive. Tous les exemples proposés pour illustrer la méthode ont été implantés et peuvent être testés avec le logiciel approprié

Génération de textes : G-TAG revisité avec les Grammaires Catégorielles Abstraites

International audienceG-TAG est un formalisme dédié à la génération de textes. Il s'appuie sur les Grammaires d'Arbres Adjoints (TAG) qu'il étend avec des notions propres permettant de construire une forme de surface à partir d'une représentation conceptuelle. Cette représentation conceptuelle est indépendante de la langue, et le formalisme G-TAG a été conçu pour la mise en œuvre de la synthèse dans une langue cible à partir de cette représentation. L'objectif de cet article est d'étudier G-TAG et les notions propres que ce formalisme introduit par le biais des Grammaires Catégorielles Abstraites (ACG) en exploitant leurs propriétés de réversibilité intrinsèque et leur propriété d'encodage des TAG. Nous montrons que les notions clefs d'arbre de g-dérivation et de lexicalisation en G-TAG s'expriment naturellement en ACG. La construction des formes de surface peut alors utiliser les algorithmes généraux associés aux ACG et certaines constructions absentes de G-TAG peuvent être prises en compte sans modification supplémentaire

A Datalog recognizer for almost affine lambda-CFGs

International audienceThe recent emergence of linguistic formalisms exclusively based on the simply-typed λ-calculus to represent both syntax and semantics led to the presentation of innovative techniques which apply to both the problems of parsing and generating natural languages. A common feature of these techniques consists in using strong relations between typing properties and syntactic structures of families of simply-typed λ-terms. Among significant results, an efficient algorithm based on Datalog programming is presented in [Kan07] for context-free grammar of almost linear λ-terms, which are linear λ-terms augmented with a restricted form of copy. We present an extension of this method to terms for which deletion is allowed

On the Membership Problem for Non-Linear Abstract Categorial Grammars

International audienceIn this paper we show that the membership problem for second order non- linear Abstract Categorial Grammars is decidable. A consequence of that result is that Montague-like semantics yield to a decidable text generation problem. Furthermore the proof we propose is based on a new tool, Higher Order Intersection Signatures, which grasps statically dynamic properties of λ-terms and presents an interest in its own