Abstract not found

We present an implemented compilation algorithm that translates HPSG into lexicalized feature-based TAG, relating concepts of the two theories. While HPSG has a more elaborated principle-based theory of possible phrase structures, TAG provides the means to represent lexicalized structures more explicitly. Our objectives are met by giving clear definitions that determine the projection of structures from the lexicon, and identify "maximal" projections, auxiliary trees and foot nodes. 1 Introduction Head Driven Phrase Structure Grammar (HPSG) and Tree Adjoining Grammar (TAG) are two frameworks which so far have been largely pursued in parallel, taking little or no account of each other. In this paper we will describe an algorithm which will compile HPSG grammars, obeying certain constraints, into TAGs. However, we are not only interested in mapping one formalism into another, but also in exploring the relationship between concepts employed in the two frameworks. HPSG is a feature-based...

Generalized Multitext Grammar (GMTG) is a synchronous grammar formalism that is weakly equivalent to

. Mildly context sensitive grammar formalisms such as multicomponent TAGs and linear context free rewrite systems have been introduced to capture the full complexity of natural languages. We show that, in a formal sense, Old Georgian can be taken to provide an example of a non-semilinear language. This implies that none of the aforementioned grammar formalisms is strong enough to generate this language. Introduction What we have in mind when we use the term syntactic invariant is, roughly speaking, a property, valid within some (formal) grammar theory, which remains "robust under slight modifications" of this theory. In the following we direct our particular attention to one such property: Semilinearity (of a language). Introducing the definition of semilinearity Parikh proved that any context free language (CFL) is semilinear (see e.g. Parikh 1966). It has been shown that there is a need to go beyond the class of all CFLs, if we want to define a formal language in terms of phr...

In some recent efforts to reduce the theoretical machinery of transformational syntax, all structures have the underlyingly order "specifier-head-complement", all movement is leftward, feature-driven, phrasal, and overt. With these developments, the movement of constituents from which material has already been extracted, "remnant movement," is increasingly common. This paper shows that these restricted transformational frameworks remain very expressive in terms of their generative power, and that although the structures they define look complex and require new parsing strategies, their coding complexity is no higher than that of traditional analyses. Furthermore, the derivations of these structures have a simplicity which is revealed by representing them as graphs of matching pairs (feature checking relations), as is done in the "proof nets" of the type logical tradition.

In this paper we discuss the following issue: How do we decide whether a certain property of language is a competence property or a performance property? Our claim is that the answer to this question is not given apriori. The answer depends on the formal devices (formal grammars and machines) available to us for describing language. We discuss this issue in the context of the complexity of processing of center embedding (of relative clauses in English) and scrambling (in German, for example) from arbitrary depths of embedding. 1 Introduction How do we decide whether a certain property of language is a competence property or a performance property? This is an old question. In this pa- The authors want to thank two referees of this paper for the very valuable comments, which helped to improve both the content and presentation of this paper. This work was partially supported by NSF Grant SBR8920230 and ARO Grant DAAH0404-94GE -0426. 2 / per, we will investigate this question in th...

A type of ‘non-traditional constituents’ motivates an extended class of Combinatory Categorial Grammars, CCGs with Generalized Type-Raised Categories (CCG-GTRC) involving variables. Although the class of standard CCGs is known to be polynomially parsable, use of variables suggests more complexity for processing GTRCs. This paper argues that polynomial parsing is still possible for CCG-GTRC from practical and theoretical points of view. First, we show that an experimental parser runs polynomially in practice on a realistic fragment of Japanese by eliminating spurious ambiguity and excluding genuine ambiguities. Then, we present a worst-case polynomial recognition algorithm for CCG-GTRC by extending the polynomial algorithm for the standard CCGs.

The paper presents a tabular interpretation for a kind of 2-Stack Automata. These automata may be used to describe various parsing strategies, ranging from purely top-down to purely bottom-up, for LIGs and TAGs. The tabnlar interpretation ensures, for all strategies, a time complexity in O(n ~) and space complexity in O(n ~) where n is the length of the input string.

This article addresses the problem that the expressive power of tree-adjoining grammars (TAGs) is too limited to deal with certain syntactic phenomena, in particular, with scrambling in freeword-order languages. The TAG variants proposed so far in order to account for scrambling are not entirely satisfying. Therefore, the article introduces an alternative extension of TAG that is based on the notion of node sharing, so-called (restricted) tree-local multicomponent TAG with shared nodes (RSN-MCTAG). The analysis of some German scrambling data is sketched in order to show that this TAG extension can deal with scrambling. Then it is shown that for RSN-MCTAGs of a specific type, equivalent simple range concatenation grammars can be constructed. As a consequence, these RSN-MCTAGs are mildly context-sensitive and in particular polynomially parsable. These specific RSN-MCTAGs probably can deal not with all scrambling phenomena, but with an arbitrarily large subset.

this paper, I will develop an alternative to these suggestions, incorporating certain insights from each. I propose that children's acquisitional difficulties result not from problems in grammatical knowledge or lexical acquisition per se, but rather from their limited abilities in performing certain types of computations. This shares some of the properties of the view advocated by Crain and his colleagues, though I propose that the child's limitations are of a grammatical nature, preventing certain types of manipulations of complex phrase structural representations. I argue that the sequence of stages we observe in the development of complex sentences is best understood as the reflection of increasing generative complexity of the underlying formal grammatical system used by the child to construct her tree structure representations. As these changes in the underlying formal grammar are triggered by some sort of maturation (see section 5), this proposal is similar in certain respects to the maturational proposals of Felix, and Borer and Wexler. It is however distinguished in what it takes to be the object of maturation: the formal machinery underlying the grammar rather than the substantive grammatical 2