This paper sketches a grammar of English relative clause constructions (including infinitival and reduced relatives) based on the notions of construction type and type constraints. Generalizations about dependency relations and clausal functions are factored into distinct dimensions contributing constraints to specific construction types in a multiple inheritance type hierarchy. The grammar presented here provides an account of extraction, pied piping and relative clause `stacking' without appeal to transformational operations, transderivational competition, or invisible (`empty') categories of any kind.

This thesis presents accounts of a range of linguistic phenomena in an extended categorial framework, and develops proposals for processing grammars set within this framework. Linguistic phenomena whose treatment we address include word order, grammatical relations and obliqueness, extraction and island constraints, and binding. The work is set within a flexible categorial framework which is a version of the Lambek calculus (Lambek, 1958) extended by the inclusion of additional type-forming operators whose logical behaviour allows for the characterization of some aspect of linguistic phenomena. We begin with the treatment of extraction phenomena and island constraints. An account is developed in which there are many interrelated notions of boundary, and where the sensitivity of any syntactic process to a particular class of boundaries can be addressed within the grammar. We next present a new categorial treatment of word order which factors apart the specification of the order of a h...

Abstract. In this paper, we present a unified feature-based theory of complement, adjunct, and subject extraction, in which there is no need either for valence reducing lexical rules or for phonologically null traces. Our analysis rests on the assumption that the mapping between argument structure and valence is defined by realization constraints which are satisfied by all lexical heads. Arguments can be realized as local dependents, in which case they are selected via the head’s valence features. Alternatively, arguments may be realized in a long-distance dependency construction, in which case they are selected via the head’s SLASH features. Furthermore, we argue that in English post-verbal adjuncts, as well as complements, are syntactic dependents selected by the verb, thus providing a uniform analysis of complement and adjunct extraction. Finally, we provide an alternative treatment of subject extraction which is subsumed by our general analysis and offer a new account of the that-trace effect. 1.

We present a detailed process theory of the moment-by-moment working-memory retrievals and associated control structure that subserve sentence comprehension. The theory is derived from the application of independently motivated principles of memory and cognitive skill to the specialized task of sentence parsing. The resulting theory construes sentence processing as a series of skilled associative memory retrievals modulated by similarity-based interference and fluctuating activation. The cognitive principles are formalized in computational form in the Adaptive Control of Thought–Rational (ACT–R) architecture, and our process model is realized in ACT–R. We present the results of 6 sets of simulations: 5 simulation sets provide quantitative accounts of the effects of length and structural interference on both unambiguous and garden-path structures. A final simulation set provides a graded taxonomy of double center embeddings ranging from relatively easy to extremely difficult. The explanation of center-embedding difficulty is a novel one that derives from the model’s complete reliance on discriminating retrieval cues in the absence of an explicit representation of serial order information. All fits were obtained with only 1 free scaling parameter fixed across the simulations; all other parameters were ACT–R defaults. The modeling results support the hypothesis that fluctuating activation and similarity-based interference are the key factors shaping working memory in sentence processing. We contrast the theory and empirical predictions with several related accounts of sentence-processing complexity.

this dissertation. I single out for special thanks first a few of the Ventura Hall crowd, including Mfirvet Eng, Nancy Wiegand, Susan Stucky (the other Mennonite formal linguist), and Kathie Carpenter, Suzanne Kemmer and Michael Barlow, with whom I have happily shared every step of the Stanford graduate pilgrimage. Next, I warmly thank Gina Wein for her competent administrative support and for her friendship. Finally, I gratefully acknowledge the strong shaping influences of the members of the Stanford linguistics faculty, who teach and also model a vibrant and professional approach to linguistic research. Representative of these scholars are the three members of my reading committee, whose work and counsel have had a profound effect on my work; I thank Joan Bresnan, Ivan Sag, and my principal advisor, Thomas Wasow, whose patience, cheerful persistence, unstinting support, solid critique, creative ideas, and common sense made the writing of this thesis possible and enjoyable. Every student should have such an advisor

An aspect of the Generalized Phrase Structure Grammar formalism proposed by Gazdar, et al. is the introduction of the notion of "slashed categories " to handle the parsing of structures, such as relative clauses, which involve unbounded dependencies. This has been implemented in Definite Clause Grammars through the technique of gap threading, in which a difference list of extracted noun phrases (gaps) is maintained. However, this technique is cumbersome, and can result in subtle soundness problems in the implemented grammars. Miller and Pareschi have proposed a method of implementing gap threading at the logical level in intuitionistic logic. Unfortunately that implementation itself suffered from serious problems, which the authors recognized. This paper builds on work first presented with Miller in which we developed a filler-gap dependency parser in Girard's linear logic. This implementation suffers from none of the pitfalls of either the traditional implementation, or the intuitioni...

It is a tacit assumption of much linguistic inquiry that all distinct derivations of a string should assign distinct meanings. But despite the tidiness of such derlvational uniqueness, there seems to be no a priori reason to assume that a gramma r must have this property. If a grammar exhibits derivational equivalence, whereby distinct derivations of a string assign the same meanings, naive exhaustive search for all derivations will be redundant, and quite possibly intractable. In this paper we show how notions of derivation-reduction and normal form can be used to avoid unnecessary work while parsing with grammars exhibiting derivational equivalence. With grammar regarded as analogous to logic, derivations are proofs; what we are advocating is proof-reduction, and normal form proof; the invocation of these logical techniques adds a further paragraph to the story of parsing-as-deduction.

Definite Clause Grammars (DCGs) have proved valuable to computational linguists since they can be used to specify phrase structured grammars. It is well known how to encode DCGs in Horn clauses. Some linguistic phenomena, such as filler-gap dependencies, are difficult to account for in a completely satisfactory way using simple phrase structured grammar. In the literature of logic grammars there have been several attempts to tackle this problem by making use of special arguments added to the DCG predicates corresponding to the grammatical symbols. In this paper we take a different line, in that we account for filler-gap dependencies by encoding DCGs within hereditary Harrop formulas, an extension of Horn clauses (proposed elsewhere as a foundation for logic programming) where implicational goals and universally quantified goals are permitted. Under this approach, filler-gap dependencies can be accounted for in terms of the operational semantics underlying hereditary Harrop formulas, in a way reminiscent of the treatment of such phenomena in Generalized Phrase Structure Grammar (GPSG). The main features involved in this new formulation of DCGs are mechanisms for providing scope to constants and program clauses along with a mild use of λ-terms and λ-conversion. 1

this paper, we will study the possibilities for applying lexical rules to the analysis of English syntax, and in particular the structure of the verb phrase. We will develop a lexicon whose empirical coverage extends to the full range of verb subcategories, complex adverbial phrases, auxiliaries, the passive construction, yes/no questions and the particularly troublesome case of predicatives. The effect of a lexical rule, in our system, will be to produce new lexical entries from old lexical entries. The similarity between our system and the metarule system of generalized phrase-structure grammar (GPSG, as presented in Gazdar, et al. 1985) is not coincidental. Our lexical rules serve much the same purpose as metarules in GPSG, which were restricted to lexical phrase structure rules. The similarity is in a large part due to the fact that with the universal phrase-structure schemes being fixed, the role of a lexical category assignment in effect determines phrase-structure in much the same way as a lexical category entry and lexical phrase-structure rule determines lexical phrase-structure in GPSG. Our lexical rules will also bear a relationship to the lexical rules found in lexical-functional grammar (LFG, see Bresnan 1982), as LFG rules are driven by the grammatical role assigned to arguments. Many of our analyses were first applied to either LFG or GPSG, as these were the first serious linguistic theories based on a notion of unification. In the process of explaining the basic principles behind categorial grammar and developing our lexical rule system, we will establish a categorial grammar lexicon with coverage of English syntactic constructions comparable to that achieved within published accounts of the GPSG or LFG frameworks. Language, at its most abstract level, i...

The purpose of this work is to investigate the process of grammatical acquisition from data. In order to do that, a computational learning system is used, composed of a Universal Grammar with associated parameters, and a learning algorithm, following the Principles and Parameters Theory. The Universal Grammar is implemented as a Unification-Based Generalised Categorial Grammar, embedded in a default inheritance network of lexical types. The learning algorithm receives input from a corpus of spontaneous child-directed transcribed speech annotated with logical forms and sets the parameters based on this input. This framework is used as a basis to investigate several aspects of language acquisition. In this thesis I concentrate on the acquisition of subcategorisation frames and word order information, from data. The data to which the learner is exposed can be noisy and ambiguous, and I investigate how these factors a#ect the learning process. The results obtained show a robust learner converging towards the target grammar given the input data available. They also show how the amount of noise present in the input data a#ects the speed of convergence of the learner towards the target grammar. Future work is suggested for investigating the developmental stages of language acquisition as predicted by the learning model, with a thorough comparison with the developmental stages of a child. This is primarily a cognitive computational model of language learning that can be used to investigate and gain a better understanding of human language acquisition, and can potentially be relevant to the development of more adaptive NLP technology.