Minimal Computation in the Minimalist Program

This paper presents a parser that embodies principles of the Minimalist Program [Chomsky 1993, 1995] and examines some related computational complexity issues. First, the parser adopts a derivational conception of syntactic operation [Epstein 1995]. Specifically, syntactic relations are completely determined by a derivational structure-building process. Second, it assumes that syntactic operations satisfy featural requirements that are inherent morphological properties of lexical items. Further, the parser uses some economy principles that prefer operations with the “least effort”. Given these, a notion of “local computation” is realized in the parser that tries to eliminate syntactically illegitimate parses as soon as possible, leading to computational efficiency. Some psycholinguistic expectations naturally fall out. 1 The Minimalist Program The essence of Chomsky’s Minimalist Program [1993, 1995] is to eliminate syntactic entities and principles that are not absolutely necessary for linguistic description and explanation. The syntactic module of the language faculty serves its role in mediating form and meaning, thus only constrained by the so-called “Bare Output Conditions” (BOC), the empirical conditions at LF (conceptual-intentional) and PF (articulatory-perceptual) interfaces. A number of conceptually natural, computationally simple Generalized Transformations (GT) are defined, for example, Merge, Move. GT operate on lexical items and compose syntactic objects from them. The relationship among syntactic objects constitutes syntactic structure. At the interfaces, the only available entities are syntactic objects and the syntactic structure they form. These entities contain inherent features of lexical items that impose constraints on PF production and LF interpretation. Syntactic operations are to deal with only these entities and to reflect these constraints – and nothing else. More specifically, a lexical item consists of a feature triple < P, S, F >, the phonological, semantic, and formal features, respectively. For instance, the S features of the verb runs specify its semantic properties, i.e. present tense, singular, etc, while its F features indicate that it has Case slots to assign. Putting phonology aside (thus PF and P features), the only conditions that LF imposes are of interpretability nature: S features are interpretable and F features are not. In this sense, syntactic operations must eliminate F and preserve S features for this LF legibility condition. What interpretations there are and how they are constructed then become properties of the structures that syntactic operations have produced. It is the nature of these syntactic operations that the Minimalist Program attempts to characterize. The aim is to reduce language universal constraints (e.g. Subjacency, ECP in the GB framework) to these general, simple operations along with some economy constraints, and to cast language variations in the form of morphological featural parameterizations – irreducible by hypothesis. Note that the interface conditions (BOC) deal with only morphological features inherent to lexical items, be formal or semantic. Since BOC are the only output constraints imposed on syntax, it is assumed that syntactic operations are feature-driven to check features. The principle Last Resort states that a syntactic operation T takes place iff T checks feature(s) or T is a necessary step for feature(s) to be checked later. Economy principle prefers operations with the “least effort”, usually defined in the number of steps in an operation, the “distance” of a movement, etc. In the rest of this paper, we adopt a derivational conception of the Minimalist Program, due to Sam Epstein [1995] and explore its computational consequences. We show that syntactic relations can be established among objects, derivationally, via a simple syntactic operation Merge. A detailed feature checking algorithm is proposed, which is embedded in a canonical parser. Beyond