A taxonomy of problems with fast parallel algorithms
Information and Control
Are search and decision programs computationally equivalent?
STOC '85 Proceedings of the seventeenth annual ACM symposium on Theory of computing
On sparseness, ambiguity and other decision problems for acceptors and transducers
3rd annual symposium on theoretical aspects of computer science on STACS 86
The method of forced enumeration for nondeterministic automata
Acta Informatica
Nondeterministic space is closed under complementation
SIAM Journal on Computing
Introduction To Automata Theory, Languages, And Computation
Introduction To Automata Theory, Languages, And Computation
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Word problems requiring exponential time(Preliminary Report)
STOC '73 Proceedings of the fifth annual ACM symposium on Theory of computing
The equivalence problem for regular expressions with squaring requires exponential space
SWAT '72 Proceedings of the 13th Annual Symposium on Switching and Automata Theory (swat 1972)
| Hi-index | 0.00 |
The goal of this paper is to study the exact complexity of several important problems concerning finite-state automata and to classify the degrees of ambiguity of nondeterministic finite-state automata. Our results are as follows: (1) Minimization of deterministic finite automata is NC^1-complete for NL. (2) Testing whether the degree of ambiguity of a nondeterministic finite automaton is exponential, or polynomial, or bounded is NC^1-complete for NL. (3) Checking whether a given nondeterministic finite automaton is unambiguous or k-ambiguous is NC^1-complete for NL, where k is some fixed constant. (4) The bounded nonuniversality problem for nondeterministic finite automata (which is the problem of deciding whether L(M) @? @S^@?^n @S^@?^n for a given nondeterministic finite automaton M and a unary integer n) is log-space complete for NP. (5) The bounded nonuniversality problem for unambiguous finite automata is in DET (the class of problems NC^1-reducible to computing the determinants of integer matrices), and for deterministic finite automata, it is NC^1-complete for NL. (6) The inequivalence problems for unambiguous and k-ambiguous finite automata are both in DET, where k is some fixed constant.