It is shown that any recognition problem solved by a polynomial time-bounded
nondeterministic Turing machine can be “reduced” to the problem of determin ing whether a …

Alternation is a generalization of nondeterminism in which existential and universal
quantitiers can alternate during the course of a computation, whereas in a nondeterministic …

A large class of classical combinatorial problems, including most of the difficult problems in
the literature of network flows and computational graph theory, are shown to be equivalent …

We argue that uniform circuit complexity introduced by Borodin is a reasonable model of
parallel complexity. Three main results are presented. First, we show that alternating Turing …

Computability and complexity theory should be of central concern to practitioners as well as
theorists. Unfortunately, however, the field is known for its impenetrability. Neil Jones's goal …

This paper deals with the evaluation of acyclic Boolean conjunctive queries in relational
databases. By well-known results of Yannakakis [1981], this problem is solvable in …

This chapter describes a Turing machine built from patterns in the Conway's Game of Life
cellular automaton. It outlines the architecture of the construction, the structure of its parts …

Recently there have been several attempts to prove that every set of strings in@@@@(ie,
recognizable in deterministic polynomial time) can be recognized in deterministic storage …

The size of an accepting computation tree of an alternating Turing machine (ATM) is
introduced as a complexity measure. Tree-size on ATM's is shown to closely correspond to …

2.2 Machine models Throughout this thesis we will be considering computing devices as
acceptors of sets of sequences, or languages. Al ternatively we may view these as 0-1 …