This paper contributes an approach for expressing non-concatenative morphological phenomena, such as stem derivation in Semitic languages, in terms of a mildly context-sensitive grammar formalism. This offers a convenient level of modelling abstraction while remaining computationally tractable. The nonparametric Bayesian framework of adaptor grammars is extended to this richer grammar formalism...

We define a generative model for a minimalist grammar formalism. We present a generalized algorithm for the application of variational bayesian inference to lexicalized mildly context sensitive grammars. We apply this algorithm to the minimalist grammar model.

This review paper will report on some recent discoveries in the area of Formal Languages, chie y by F. Otto, G. Buntrock and G. Niemann. These discoveries have pointed out certain break-throughs connected with the concept of growing contextsensitive languages, which originated in the 1980's with a paper by E. Dahlhaus and M.K. Warmuth. One important result is that the deterministic growing cont...

In this study, a context-sensitive grammar is suggested to model various forms of RNA secondary structures, especially pseudoknots. Comparing with a conventional context-free grammar used to model secondary structures of RNA sequences, the use of context-sensitive grammar gives us an advantage of more natural representation of pseudoknots. The suggested grammar directly reflects the appearance ...

Context-free grammars are widely used for the simple form of their rules. A derivation step consists of the choice of a nonterminal of the sentential form and of an application of a rule rewriting it. Several regulations of the derivation process have been studied to increase the power of context-free grammars. In the resulting grammars, however, not only the symbols to be rewritten are restric...

This survey paper describes several extensions of context-free grammars as defined in the Chomsky hierarchy. These augmentations use a variety of different strategies to create grammars that generate all context-free and some context-sensitive languages. The basic concepts of each of these extensions will be examined, as well as whether the enhanced grammars inherited some of the desirable prop...

A finitely generated group is called a Church-Rosser group (growing contextsensitive group) if it admits a finitely generated presentation for which the word problem is a Church-Rosser (growing context-sensitive) language. Although the ChurchRosser languages are incomparable to the context-free languages under set inclusion, they strictly contain the class of deterministic context-free language...

A large body of research in machine learning is concerned with supervised learning from examples. The examples are typically represented as vectors in a multi-dimensional feature space (also known as attribute-value descriptions). A teacher partitions a set of training examples into a finite number of classes. The task of the learning algorithm is to induce a concept from the training examples....

Among the well-established variety of formal grammar types providing a mildly context-sensitive grammar (MCSG) formalism in the sense of Joshi (1985), Stabler’s minimalist grammars (MGs) (Stabler 1997, 1999) come closest to modeling the tools used in the Chomskyan branch of generative syntax known as “minimalism” (Chomsky 1995, 2000, 2001). Interestingly, without there being a rise in (at least...

L systems generalise context-free grammars by incorporating parallel rewriting, and generate languages such as EDT0L and ET0L that are strictly contained in the class of indexed languages. In this paper we show that many of the languages naturally appearing in group theory, and that were known to be indexed or context-sensitive, are in fact ET0L and in many cases EDT0L. For instance, the langua...