scispace - formally typeset
Journal ArticleDOI

Nondeterministic space is closed under complementation

Neil Immerman
- 01 Oct 1988 - 
- Vol. 17, Iss: 5, pp 935-938
Reads0
Chats0
TLDR
It immediately follows that the context-sensitive languages are closed under complementation, thus settling a question raised by Kuroda.
Abstract
In this paper we show that nondeterministic space $s(n)$ is closed under complementation for $s(n)$ greater than or equal to $\log n$. It immediately follows that the context-sensitive languages are closed under complementation, thus settling a question raised by Kuroda [Inform. and Control, 7 (1964), pp. 207–233].

read more

Citations
More filters
Book

Structural Complexity I

TL;DR: This volume is written for undergraduate students who have taken a first course in Formal Language Theory and presents the basic concepts of structural complexity, thus providing the background necessary for the understanding of complexity theory.
Journal ArticleDOI

Computation in networks of passively mobile finite-state sensors

TL;DR: The computational power of networks of small resource-limited mobile agents and two new models of computation based on pairwise interactions of finite-state agents in populations of finite but unbounded size are defined.
Book ChapterDOI

A catalog of complexity classes

TL;DR: This chapter discusses the concepts needed for defining the complexity classes, a set of problems of related resource-based complexity that can be solved by an abstract machine M using O(f(n) of resource R, where n is the size of the input.
Journal ArticleDOI

On uniformity within NC 1

TL;DR: It is shown that Immerman's families of circuits defined by first-order formulas and a uniformity corresponding to Buss' deterministic log-time reductions are equivalent, leading to a natural notion of uniformity for low-level circuit complexity classes.
Journal ArticleDOI

The method of forced enumeration for nondeterministic automata

R. Szelepcsényi
- 01 Nov 1988 - 
TL;DR: Every family of languages, recognized by nondeterministic L(n) tape-bounded Turing machines, where L( n)≥logn, is closed under complement, and as a special case, the family of context-sensitive languages isclosed under complement.
References
More filters
Journal ArticleDOI

Relationships between nondeterministic and deterministic tape complexities

TL;DR: The amount of storage needed to simulate a nondeterministic tape bounded Turingmachine on a deterministic Turing machine is investigated and a specific set is produced, namely the set of all codings of threadable mazes, such that, if there is any set which distinguishes nondeter microscopic complexity classes from deterministic tape complexity classes, then this is one such set.
Journal ArticleDOI

Relational queries computable in polynomial time

TL;DR: The rotary ball valve includes a generally annular seal which is held in place by an edge anchored annular retainer which is oversized for the valve housing and on installation resides in a state of compression.
Journal ArticleDOI

A taxonomy of problems with fast parallel algorithms

TL;DR: An attempt is made to identify important subclasses of NC and give interesting examples in each subclass, and a new problem complete for deterministic polynomial time is given, namely, finding the lexicographically first maximal clique in a graph.
Journal ArticleDOI

Languages that capture complexity classes

TL;DR: It is shown that projection translations are a uniform version of Valiant’s projections, and that the usual complete problems remain complete via these very restrictive reductions.