Principles and Implementation of Deductive Parsing

We present a system for generating parsers based directly on the metaphor of parsing as deduction. Parsing algorithms can be represented directly as deduction systems, and a single deduction engine can interpret such deduction systems so as to implement the corresponding parser. The method generalizes easily to parsers for augmented phrase structure formalisms, such as definite-clause grammars and other logic grammar formalisms, and has been used for rapid prototyping of parsing algorithms for a variety of formalisms including variants of tree-adjoining grammars, categorial grammars, and lexicalized context-free grammars.Comment: 69 pages, includes full Prolog cod

Unifying synchronous tree-adjoining grammars and tree transducers via bimorphisms.

We place synchronous tree-adjoining grammars and tree transducers in the single overarching framework of bimorphisms, continuing the unification of synchronous grammars and tree transducers initiated by Shieber (2004). Along the way, we present a new definition of the tree-adjoining grammar derivation relation based on a novel direct inter-reduction of TAG and monadic macro tree transducers.Engineering and Applied Science

Exploring the underspecified world of lexicalized tree adjoining grammars

This paper presents a precise characterization of the underspecification found in Lexicalized Tree Adjoining Grammars, and shows that, in a sense, the same degree of underspecification is found in Lexicalized D-Tree Substitution Grammars. Rather than describing directly the nature of the elementary objects of the grammar, we achieve our objective by formalizing the way in which underspecification in the derived objects is interpreted: i.e., how trees are read off from derived tree descriptions. Valid tree descriptions for ltag turn out to be those that have a single acceptable interpretation, whereas those for ldsg may have multiple interpretations. In other respects, there is no difference in the way in which ltag and ldsg tree descriptions are interpreted

On the Relation between Context-Free Grammars and Parsing Expression Grammars

Context-Free Grammars (CFGs) and Parsing Expression Grammars (PEGs) have several similarities and a few differences in both their syntax and semantics, but they are usually presented through formalisms that hinder a proper comparison. In this paper we present a new formalism for CFGs that highlights the similarities and differences between them. The new formalism borrows from PEGs the use of parsing expressions and the recognition-based semantics. We show how one way of removing non-determinism from this formalism yields a formalism with the semantics of PEGs. We also prove, based on these new formalisms, how LL(1) grammars define the same language whether interpreted as CFGs or as PEGs, and also show how strong-LL(k), right-linear, and LL-regular grammars have simple language-preserving translations from CFGs to PEGs