Formal languages
On measuring nondeterminism in regular languages
Information and Computation
On the relation between ambiguity and nondeterminism in finite automata
Information and Computation
Measures of nondeterminism for pushdown automata
Journal of Computer and System Sciences
ACM SIGACT News
Pushdown automata with bounded nondeterminism and bounded ambiguity
Theoretical Computer Science - Special issue: Latin American theoretical informatics
Context-free languages and pushdown automata
Handbook of formal languages, vol. 1
Grammars with controlled derivations
Handbook of formal languages, vol. 2
An Infinite Hierarchy of Context-Free Languages
Journal of the ACM (JACM)
Regular Closure of Deterministic Languages
SIAM Journal on Computing
Acta Cybernetica
Regulated Rewriting in Formal Language Theory
Regulated Rewriting in Formal Language Theory
Introduction to Formal Language Theory
Introduction to Formal Language Theory
Refining nondeterminism below linear time
Journal of Automata, Languages and Combinatorics - Third international workshop on descriptional complexity of automata, grammars and related structures
Computations with a restricted number of nondeterministic steps.
Computations with a restricted number of nondeterministic steps.
The Mathematical Theory of Context-Free Languages
The Mathematical Theory of Context-Free Languages
Measuring nondeterminism in pushdown automata
Journal of Computer and System Sciences
Introduction to Automata Theory, Languages, and Computation (3rd Edition)
Introduction to Automata Theory, Languages, and Computation (3rd Edition)
One-Turn Regulated Pushdown Automata and Their Reduction
Fundamenta Informaticae
Context-dependent nondeterminism for pushdown automata
Theoretical Computer Science
Handbook of Discrete and Combinatorial Mathematics, Second Edition
Handbook of Discrete and Combinatorial Mathematics, Second Edition
Descriptional complexity of (un)ambiguous finite state machines and pushdown automata
RP'10 Proceedings of the 4th international conference on Reachability problems
Regulated Nondeterminism in Pushdown Automata: The Non-Regular Case
Fundamenta Informaticae - Non-Classical Models of Automata and Applications
Fundamenta Informaticae - Non-Classical Models of Automata and Applications II
Hi-index | 5.23 |
A generalization of pushdown automata towards regulated nondeterminism is studied. The nondeterminism is governed in such a way that the decision, whether or not a nondeterministic rule is applied, depends on the whole content of the stack. More precisely, the content of the stack is considered as a word over the stack alphabet, and the pushdown automaton is allowed to act nondeterministically, if this word belongs to some given set R of control words. Otherwise its behavior is deterministic. It turns out that non-context-free languages can be accepted if R is a context-free and non-regular language. On the other hand, if the control sets R are regular languages, then the resulting devices are not more powerful than nondeterministic pushdown automata. This raises the natural question of the relations between the structure and complexity of regular sets R on one hand and the computational capacity of the corresponding R-PDA on the other hand. The main result of the paper shows that an infinite proper hierarchy of regular control sets leads to an infinite proper hierarchy of the corresponding language classes. Additionally, closure properties and decision problems of these language classes are investigated.