Context-Sensitive String Languages and Eecognizable Picture Languages
نویسندگان
چکیده
The theorem stating that the family of frontiers of recognizable tree languages is exactly the family of context-free languages (see J. Mezei and J. B. Wright, 1967, Inform. and Comput. 11, 3 29), is a basic result in the theory of formal languages. In this article, we prove a similar result: the family of frontiers of recognizable picture languages is exactly the family of context-sensitive languages. ] 1997 Academic Press
منابع مشابه
Describing Computations by (bounded) Local Sets
We introduce the deenition of local structures as description of computations to recognize strings. Then, we identify the type of local structures corresponding to regular, context free and context sensitive languages, respectively and give a uniform characterization of those families in Chomsky's hierachy in terms of projection of frontiers of local sets of structures. In the second part, we c...
متن کاملOgden’s Lemma for Random Permitting and Forbidding Context Picture Languages and Table-Driven Context-Free Picture Languages
Random context picture grammars are used to generate pictures through successive refinement. There are three important subclasses of random context picture grammars, namely random permitting context picture grammars, random forbidding context picture grammars and table-driven context-free picture grammars. These grammars generate the random permitting context picture languages, random forbiddin...
متن کاملTransforming Linear Context-Free Rewriting Systems into Minimalist Grammars
The type of a minimalist grammar (MG) as introduced by Stabler [11, 12] provides an attempt of a rigorous algebraic formalization of the new perspectives adopted within the linguistic framework of transformational grammar due to the change from GB–theory to minimalism. Michaelis [6] has shown that MGs constitute a subclass of mildly context–sensitive grammars in the sense that for each MG there...
متن کاملUsing Alternating Words to Describe Symbolic Pictures
In this paper we present the concepts of drawn symbolic picture and symbolic picture. Such notions have been conceived as an extension of the concept of drawn pictures which was introduced by Maurer, Rozenberg and Welzl [31]. We provide a string description of such pictures. It consists of alternating words, i.e. strings whose letters are in alternation from an alphabet of symbols and an alphab...
متن کاملEpsilon-Free Grammars and Lexicalized Grammars that Generate the Class of the Mildly Context-Sensitive Languages
This study focuses on the class of string languages generated by TAGs. It examines whether the class of string languages can be generated by some epsilon-free grammars and by some lexicalized grammars. Utilizing spine grammars, this problem is solved positively. This result for spine grammars can be translated into the result for TAGs.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Inf. Comput.
دوره 138 شماره
صفحات -
تاریخ انتشار 1997