On the Complexity of Szilard Languages of Regulated Grammars

  title={On the Complexity of Szilard Languages of Regulated Grammars},
  author={Liliana Cojocaru and Erkki M{\"a}kinen},
We investigate computational resources used by alternating Turing machines (ATMs) to accept Szilard languages (SZLs) of regulated rewriting grammars. The main goal is to relate these languages to lowlevel complexity classes such as NC1 and NC2. We focus on the derivation process in random context grammars (RCGs) with context-free rules. We prove that unrestricted SZLs and leftmost-1 SZLs of RCGs can be accepted by ATMs in logarithmic time and space. Hence, these languages belong to the UE… 

On some derivation mechanisms and the complexity of their Szilard languages

Searching for Traces of Communication in Szilard Languages of Parallel Communicating Grammar Systems - Complexity Views

It is proved that the classes of SZLs of returning centralized and non-returning non-centralized PCGSs are included in circuit complexity class \({\mathcal N}{\ mathcal C}^1\).

Regulated Grammars and Automata

This is the first book to offer key theoretical topics and terminology concerning regulated grammars and automata. They are the most important language-defining devices that work under controls

Chapter 6 One-Sided Versions of Random Context Grammars

It is demonstrated that propagating versions of one-sided random context grammars characterize the family of context-sensitive languages, and with erasing rules, they characterize theFamily of recursively enumerable languages.

One-Sided Random Context Grammars with Leftmost Derivations

The generative power of one-sided random context grammars working in a leftmost way is studied and three types of leftmost derivations to one- sided random context Grammars are introduced and proved.

Advanced Studies on the Complexity of Formal Languages

Advanced Studies on the Complexity of Formal Languages concludes with a discussion of the role of semantics in the development of knowledge of language structure and its role in language design.



Classes of Szilard Languages in NC^1

We prove that Szilard languages of context-free grammars can be accepted by an indexing alternating Turing machine (indexing ATM) in logarithmic time and space. The same result holds for leftmost

The Tape Complexity of Some Classes of Szilard Languages

  • Y. Igarashi
  • Computer Science, Linguistics
    SIAM J. Comput.
  • 1977
The main results are that $\log n$ is the optimal tape bound for on-line deterministic Turing machines which recognize Szilard languages of context-free grammars, and it is also the optimal Tape bound for off-line Deterministic Turing Machines which recognize leftmost Szilards of phrase structure grammar.

Szilard Languages of IO-Grammars

Regulated Rewriting in Formal Language Theory

This book presents 25 different regulating mechanisms by definitions, examples and basic facts, especially concerning hierarchies, as well as selective substitution grammars as one common generalization.

Renaming and Erasing in Szilard Languages

It is shown that arbitrary homomorphisms do not have more generating power than nonerasing ones except that they generate the empty word.

A Pumping Lemma for Random Permitting Context Languages

On the Leftmost Derivation in Matrix Grammars

The main point of this paper is the systematic study of all possibilities of defining leftmost derivation in matrix grammars and finds a characterization of the recursively enumerable languages for matrix Grammars with the leftmost restriction defined on classes of a given partition of the nonterminal alphabet.

Formal translations and the containment problem for Szilard languages

It is shown that one can determine whether a given grammar fits another given grammar, and it is established that the containment problem for Szilard languages is decidable.

Petri Nets and Szilard Languages

Associate Languages and Derivational Complexity of Formal Grammars and Languages

  • E. Moriya
  • Linguistics, Computer Science
    Inf. Control.
  • 1973