Typed Feature Structures Research Articles

The lexical constructional model meets syntax: guidelines of the formalized lexical-constructional model (FL_CxG )

This paper offers the basic guidelines of a formalized version of the Lexical Constructional Model (LCM; Ruiz de Mendoza & Mairal Usón, 2008, 2011; Ruiz de Mendoza & Galera, 2014), the Formalized Lexical-Constructional Grammar (FL_CxG), which will pave the way for future computational developments, such as parsers or lexical databases. The FL_CxG deploys (i) the typologically oriented syntactic apparatus of Role and Reference Grammar (Van Valin, 2005; Van Valin & LaPolla, 1997), (ii) the catalogue of constructional units arranged in a 4-layer typology, as proposed by the LCM, and (iii) some insights for semantic representations from the Generative Lexicon Theory (Pustejovsky, 1995; Pustejovsky & Batiukova, 2019), and Minimal English (Goddard, 2018). All the components of the FL_CxG (lexical units and construct(ion)s) are formally encoded as Typed Feature Structures in the format of Attribute Value Matrixes. These units are to be understood as constraints operating in the unification processes which underlie the generation/decoding of a given fragment of language.

Pseudo-partitives in English: an HPSG analysis

Pseudo-partitives are strings of the form [N1– of – N2] in which N1denotes a quantity or amount of whatever it is that N2denotes and in which N2is a bare nominal. Such strings come in two types, depending on whether the combination shares thenumbervalue of N1or N2. The first type can be analyzed along familiar lines, but the second one is a hard nut to crack. The article presents existing treatments, showing that they all involve departures from independently motivated principles. As an alternative we propose an analysis that is cast in the Typed Feature Structure notation of Head-driven Phrase Structure Grammar. It handles both types of pseudo-partitives, arguing that N1and the prepositionofare complement-selecting heads if thenumbervalue is shared with N1, while N1and the preposition are head-selecting functors if thenumbervalue is shared with N2. The switch from head to functor status is characteristic of grammaticalization and is shown to affect pseudo-partitives with a quantifier noun or a collection noun as N1, but not pseudo-partitives with a measure noun or collection noun. Examples and quantitative data are extracted from COCA.

An HPSG approach to Chinese syllable structure and tone sandhi

In Head-driven Phrase Structure Grammar (HPSG), the phonological module has been strikingly underinvestigated compared to other parts of the grammar. To remedy this situation, the aims of this study are both theoretical and empirical. We employ revised Typed Feature Structures (TFSs) to describe a number of phonological structures in Mandarin Chinese, mostly concerned with syllable structure and tone, based on the X-bar approach to the syllable structure of Mandarin (van de Weijer, 2012; van de Weijer and Zhang, 2008; Zhang, 2008). Specifically, we integrate tone features in the HPSG framework, and analyze tone sandhi (TS) by way of TFSs and constraints. We demonstrate that the enriched definitions and constraints using TFSs in phonology, like in morphology and syntax in HPSG, can successfully capture the relevant phonological generalizations and are therefore a step on the way toward a more comprehensive HPSG account of Mandarin grammar, illustrating its advantages such as simplicity, constructional consistency, modularity and facilitating interface description.

Analogy-based morphology: The Kasem number system

This paper presents a formalization of proportional analogy using typed feature structures, which retains all key elements of analogical models of morphology. With the Kasem number system as an example, I show that using this model it is possible to express partial analogies which are unified into complete analogies. The analysis presented is accompanied by a complete TRALE implementation.

Representing morphological tone in a computational grammar of Hausa

In this paper I shall discuss the representation of morphological tone in Hausa, as implemented in a computational grammar of the language, referred to as HaG, which has been developed within the framework of Head-driven Phrase Structure Grammar. Based on an in-depth study of segmental and suprasegmental properties manipulated by morphological processes, I shall argue that two fundamental insights from Autosegmental Phonology needs to be seamlessly integrated into typed feature structure grammars of languages with grammatical tone, namely (i) the systematic separation of tonal and metrical information from the string of consonants and vowels, and (ii) the possibility of tonal spreading, i.e. the possibility for a tonal specification to be assigned to an arbitrary number of adjacent tone-bearing units (syllables). To this end, I present a formalisation of tonal melodies in terms of typed list constraints that implement a notion of tonal spreading, allowing for an underspecified description of tonal melodies, independent of the number of tone-bearing units. I shall finally show that this minimal encoding is sufficient and flexible enough to capture the range of suprasegmental phenomena in Hausa.

Implementing semantic frames as typed feature structures with XMG

This work presents results on the integration of frame-based representations into the framework of eXtensible MetaGrammar (XMG). Originally XMG allowed for the description of tree-based syntactic structures and underspecified representations of predicate-logical formulae, but the representation of frames as a sort of typed feature structure, particularly type unification, was not supported. Therefore, we introduce an extension that is capable of handling frame representations directly by means of a novel <frame>-dimension. The aim is not only to make possible a straightforward specification of frame descriptions, but also to offer various ways to specify constraints on types, be it as a contiguous type hierarchy or a loose set of feature structure constraints. The presented extensions to XMG are fully operational in a new prototype.

Variable morphotactics in Information-based Morphology

We address variable morphotactics, the phenomenon of order variability of morphs, in the context of inflectional morphology. Based on an extended discussion of cross-linguistic variation, including conjugation in Nepali, Fula, Swahili, Chintang and Italian, and nominal declension in Ostyak and Mari, we propose a canonical typology that identifies different deviations from strict ordering. Following a discussion of previous approaches to the problem, we propose Information-based Morphology, an inferential-realisational and model-theoretic approach to morphology couched in a logic of typed feature structures. Within this formal theory, we develop detailed analyses of the core cases in the typology and show how different types and degrees of deviation from the canon can be pin-pointed in the relative complexity of the rule type hierarchies that model the data. Furthermore, we show that complex deviations, as attested in Mari, can be understood as combinations of more basic deviations.

Ivan A. Sag

Ivan A. Sag

Parsing the Wh-Interrogative Construction in Korean

Korean is a wh-in situ language where the wh-expression stays in situ with an oblig-atory Q-particle marking its interrogative scope. This paper briefly reviews some basic properties of the Wh-questin construction in Korean and shows how a typed feature structure grammar, HPSG (Pollard and Sag 1994, Sang et al. 2003), together with the notions of ``type hierarchy`` and ``constructions``, can provide a robust basis for parsing the wh-construction in the language. We show that this system induces robust syntactic structures as well as enriched semantic representations for real-time applications such as machine transla-tion, which require deep processing of the phenomena concerned. (KANGNAM University and Kyung Hee University)

Parsing Intentions of Speech

This paper is aimed at revealing the inner structures of intentions of speech through demonstrating a method of parsing intentions of speech. The intentions of speech are parsed separately, which is inspired by Searle's notation ( ) . In this research, both the propositional content and the illocutionary forces are represented as semantic frames, the categories of which are combined together with syntactic rules of Categorial Grammar. This method is implemented in a grammar system programed in ALE a logic programming language based on the logic of Typed Feature Structures.

A unified approach to VP-ellipsis and VP-anaphora

It is known that VP-ellipsis and VP-anaphora are typologically different phenomena. English has VP-ellipses whereas Korean has VP-anaphora. The goals of this paper are (i) to develop a unified algorithm which can analyze these two different phenomena and (ii) to explain them using the developed resolution algorithm. In order to analyze these phenomena, this paper incorporates Jager's anaphora resolution mechanism (2010) into the typed feature structure formalism of Head-driven Phrase Structure Grammar (HPSG). In this paper, VP-ellipsis and VP-anaphora are analyzed as follows. First, English do and Korean kuleha-ta are introduced with the Geach value, and this value is changed with a slash-elimination rule. Then, one constituent combines with another by ordinary syntactic rules, while the information on the target predicate is percolated up. When a potential source appears, a slash-introduction rule is applied. Then, the source predicate activates the VP-resolution rule, and the target predicate is connected with the source in the semantic representations.

Symmetric and Asymmetric Properties in Korean Verbal Coordination: A Computational Implementation

Of the coordination structures in Korean, the symmetric and asymmetric properties of verbal coordination have challenged both theoretical and computational approaches. This paper shows how a typed feature structure grammar, HPSG, together with the notions of ``type hierarchy`` and ``constructions``, can provide a robust basis for parsing (un)tensed verbal coordination as well as pseudo-coordination found in the language. We show that the analysis sketched here and computationally implemented in the existing resource grammar for Korean, Korean Resource Grammar (KRG), can yield proper syntactic structures as well as enriched semantic representations for real-time applications such as machine translation. (Kyung Hee University and Kangnam University)

Converting CCGs into typed feature structure grammars

In this paper, we report on a transformation scheme that turns a Categorial Grammar, more specifically, a Combinatory Categorial Grammar (CCG; see Baldridge, 2002) into a derivation- and meaning-preserving typed feature structure (TFS) grammar. We describe the main idea which can be traced back at least to work by Karttunen (1986), Uszkoreit (1986), Bouma (1988), and Calder et al. (1988). We then show how a typed representation of complex categories can be extended by other constraints, such as modes, and indicate how the Lambda semantics of combinators is mapped into a TFS representation, using unification to perform perform alpha-conversion and beta-reduction (Barendregt, 1984). We also present first findings concerning runtime measurements, showing that the PET system, originally developed for the HPSG grammar framework, outperforms the OpenCCG parser by a factor of 8–10 in the time domain and a factor of 4–5 in the space domain.

Implementation of Korean Syllable Structures in the Typed Feature Structure Formalism

It has been known that the syllable structures in Korean are different from those in English. The goal of this paper is to provide computational implementations for Korean syllable structures in the typed feature structure formalism. The system that we adopted in this paper is the Linguistic Knowledge Building system. We first implemented the type hierarchies and AVMs for segment and suprasegment. The types consonant and vowel were included under the type segment, and the various different types were included under the type suprasegment for syllable structures. Then, we provided the implementational rules for syllable structures. Unlike English syllabification, it has been known that onset and nucleus form a unit in Korean, which is called core. Accordingly, we provided the rules for onset, nucleus, and coda; then, the rules for core and syllable were provided to combine segments into syllable structures. This paper also employed the type nf to solve the ambiguity problems. (Chungnam National University & Hannam University)

Korean comparative constructions: A constraint-based approach and computational implementation

The complexity of comparative constructions in each language has given challenges to both theoretical and computational analyses. This paper first identifies types of comparative constructions in Korean and discusses their main grammatical properties. It then builds a syntactic parser couched upon the typed feature structure grammar, HPSG and proposes a context-dependent interpretation for the comparison. To check the feasibility of the proposed analysis, we have implemented the grammar into the existing Korean Resource Grammar. The results show us that the grammar we have developed here is feasible enough to parse Korean comparative sentences and yield proper semantic representations though further development is needed for a finer model for contextual information.

Parsing Korean Comparative Constructions in a Typed-Feature Structure Grammar

types of comparative constructions in Korean and discusses their main grammatical properties. It then builds a syntactic parser couched upon the typed feature structure grammar, HPSG and proposes a context-dependent interpretation for the comparison. To check the feasibility of the proposed analysis, we have implemented the grammar into the existing Korean Resource Grammar. The results show us that the grammar we have developed here is feasible enough to parse Korean comparative sentences and yield proper semantic representations though further development is needed for a ner model for contextual information.

Rule-based information extraction from patients’ clinical data

The paper describes a rule-based information extraction (IE) system developed for Polish medical texts. We present two applications designed to select data from medical documentation in Polish: mammography reports and hospital records of diabetic patients. First, we have designed a special ontology that subsequently had its concepts translated into two separate models, represented as typed feature structure (TFS) hierarchies, complying with the format required by the IE platform we adopted. Then, we used dedicated IE grammars to process documents and fill in templates provided by the models. In particular, in the grammars, we addressed such linguistic issues as: ambiguous keywords, negation, coordination or anaphoric expressions. Resolving some of these problems has been deferred to a post-processing phase where the extracted information is further grouped and structured into more complex templates. To this end, we defined special heuristic algorithms on the basis of sample data. The evaluation of the implemented procedures shows their usability for clinical data extraction tasks. For most of the evaluated templates, precision and recall well above 80% were obtained.

Dealing With Complex Linguistic Annotations Within a Language Processing Framework

In this paper we present AWA, a general purpose Annotation Web Architecture for representing, storing, and accessing the information produced by different linguistic processors. The objective of AWA is to establish a coherent and flexible representation scheme that will be the basis for the exchange and use of linguistic information. In morphologically-rich languages as Basque it is necessary to represent and provide easy access to complex phenomena such as intraword structure, declension, derivation and composition features, constituent discontinousness (in multiword expressions) and so on. AWA provides a well-suited schema to deal with these phenomena. The annotation model relies on XML technologies for data representation, storage and retrieval. Typed feature structures are used as a representation schema for linguistic analyses. A consistent underlying data model, which captures the structure and relations contained in the information to be manipulated, has been identified and implemented. AWA is integrated into LPAF, a multilayered Language Processing and Annotation Framework, whose goal is the management and integration of diverse NLP components and resources. Moreover, we introduce EULIA, an annotation tool which exploits and manipulates the data created by the linguistic processors. Two real corpora have been processed and annotated within this framework.

The information structure of Danish grammar constructions

This paper addresses the issue of how information structure can be accounted for in a formal grammar of Danish. Three information structure features – topic, focus and background – are discussed, and it is shown how they are instantiated in a number of different grammatical constructions from a corpus of spoken Danish. Prosodic, syntactic and information structure constraints characterising the various constructions are represented as typed feature structures following Head-driven Phrase Structure Grammar (HPSG), and the constructions themselves are ordered in a type hierarchy. The proposed approach modifies and extends earlier HPSG-based accounts by integrating information structure as a dimension of phrasal and clausal grammar constructions.

Towards automated processing of clinical Finnish: Sublanguage analysis and a rule-based parser

Introduction In this paper, we present steps taken towards more efficient automated processing of clinical Finnish, focusing on daily nursing notes in a Finnish Intensive Care Unit (ICU). First, we analyze ICU Finnish as a sublanguage, identifying its specific features facilitating, for example, the development of a specialized syntactic analyser. The identified features include frequent omission of finite verbs, limitations in allowed syntactic structures, and domain-specific vocabulary. Second, we develop a formal grammar and a parser for ICU Finnish, thus providing better tools for the development of further applications in the clinical domain. Methods The grammar is implemented in the LKB system in a typed feature structure formalism. The lexicon is automatically generated based on the output of the FinTWOL morphological analyzer adapted to the clinical domain. As an additional experiment, we study the effect of using Finnish constraint grammar to reduce the size of the lexicon. The parser construction thus makes efficient use of existing resources for Finnish. Results The grammar currently covers 76.6% of ICU Finnish sentences, producing highly accurate best-parse analyzes with F-score of 91.1%. We find that building a parser for the highly specialized domain sublanguage is not only feasible, but also surprisingly efficient, given an existing morphological analyzer with broad vocabulary coverage. The resulting parser enables a deeper analysis of the text than was previously possible.