Pregroups had been conceived as an algebraic tool to recognize grammatically well-formed sentences in natural languages [3]. Here we wish to use pregroups to recognize well-formed chords of pitches, for a given definition of those chords. We show how a judicious choice of basic and simple types allows a context-free grammatical description. Then we use the robustness property to extend the set ...

This paper investigates whether surprisal theory can account for differential processing difficulty in the NP-/S-coordination ambiguity in Dutch. Surprisal is estimated using a Probabilistic Context-Free Grammar (PCFG), which is induced from an automatically annotated corpus. We find that our lexicalized surprisal model can account for the reading time data from a classic experiment on this amb...

Probabilistic Context-Free Grammars have been unsuccessful in learning natural language, due to the complexity of the task. Considerable research has been conducted into methods of reducing the complexity of PCFG learning. This paper reports the progress of work in extending one particular method of constraining PCFG learning providing partial grammars to improve rule generation. We discuss wha...

In this paper, we introduce the notions of context-sensitive and TOL collage grammars as generalizations of context-free collage grammars. Both kinds of picture generating devices are more powerful than the context-free case. Nevertheless, the sizes of collages in a TOL collage language can be shown to grow at most exponentially. In contrast to this, there are no such bounds for context-sensiti...

The present paper introduces and discusses generalized scattered context grammars that are based upon sequences of productions whose left-hand sides are formed by nonterminal strings, not just single nonterminals. It places two restrictions on the derivations in these grammars. More specifically, let k be a positive integer. The first restriction requires that all rewritten symbols occur within...

This paper describes the Omphalos Context-Free Grammar Learning Competition held as part of the International Colloquium on Grammatical Inference 2004. The competition was created in an effort to promote the development of new and better grammatical inference algorithms for context-free languages, to provide a forum for the comparison of different grammatical inference algorithms and to gain in...

In this paper we prove the Chomsky Conjecture (all languages recognized by the Lambek calculus are context-free) for both the full Lambek calculus and its product-free fragment. For the latter case we present a construction of context-free grammars involving only product-free types.

Lambek [13] introduces pregroups as a new framework for syntactic structure. In this paper we prove some new theorems on pregroups and study grammars based on the calculus of free pregroups. We prove that these grammars are equivalent to context-free grammars. We also discuss the relation of pregroups to the Lambek calculus.

It is well known that, for context-free grammars, a leftmost derivation of a sentence univocally defines its syntactical tree; the construction of this tree consists of an iterative procedure during which two successive strings in the leftmost derivation are compared (see, e.g., [1, 2]). These -o r similar--properties do not hold for leftmost derivations in general phrase-structure grammars [3-...

In CD grammar systems, the rewriting process is distributed over component grammars that take turns in the derivation of new symbols. Team automata however collaborate by synchronising their actions. Here we investigate how to transfer this concept of synchronisation to grammars by defining grammar teams that agree on the generation of shared terminal symbols based on a novel notion of competen...