Showing papers on "Deterministic pushdown automaton published in 1993"
TL;DR: This paper constructs, in O( n log n ) time, for a given ground term equation system E and given ground trees p 1,…, p k, a deterministic tree automaton recognizing the congruential tree language [p1] ↔ ∗ E ∪…∪[pk] ↓ E.
18 citations
Journal Article•
17 citations
05 Jul 1993
TL;DR: It is shown that nondeterministic two-way reversal-bounded multicounter machines are effectively equivalent to finite automata on unary languages, and hence their emptiness, containment, and equivalence problems are decidable also.
Abstract: We look at some decision questions concerning two-way counter machines and obtain the strongest decidable results to date concerning these machines. In particular, we show that the emptiness, containment, and equivalence problems are decidable for two-way counter machines whose counter is reversal-bounded (i.e., the counter alternates between increasing and decreasing modes at most a fixed number of times). We use this result to give a simpler proof of a recent result that the emptiness, containment, and equivalence problems for two-way reversal-bounded pushdown automata accepting bounded languages (i.e., subsets of w 1 * ... w k * for some nonnull words w1,...,wk) are decidable. Other applications concern decision questions about simple programs. Finally, we show that nondeterministic two-way reversal-bounded multicounter machines are effectively equivalent to finite automata on unary languages, and hence their emptiness, containment, and equivalence problems are decidable also.
17 citations
25 Feb 1993
TL;DR: The equivalence between the family of recognizable languages over infinite traces and deterministic asynchronous cellular Muller automata is shown, giving a proper generalization of McNaughton's Theorem from infinite words to infinite traces.
Abstract: This paper shows the equivalence between the family of recognizable languages over infinite traces and deterministic asynchronous cellular Muller automata. We thus give a proper generalization of McNaughton's Theorem from infinite words to infinite traces. Thereby we solve one of the main open problems in this field. As a special case we obtain that every closed (w.r.t. the independence relation) word language is accepted by some I-diamond deterministic Muller automaton. We also determine the complexity of deciding whether a deterministic I-diamond Muller automaton accepts a closed language.
15 citations
TL;DR: It is shown that two-way reversal-bounded push-down automata over bounded languages (i.e., subsets of for some distinct symbols a1,…, ak) are equivalent to two- way reversal- bounded counter machines.
Abstract: It is known that two-way pushdown automata are more powerful than two-way counter machines. The result is also true for the case when the pushdown store and counter are reversal-bounded. In contrast, we show that two-way reversal-bounded push-down automata over bounded languages (i.e., subsets of for some distinct symbols a1,…, ak) are equivalent to two-way reversal-bounded counter machines. We also show that, unlike the unbounded input case, two-way reversal-bounded pushdown automata over bounded languages have decidable emptiness, equivalence and containment problems.
14 citations
TL;DR: Decidability of the equivalence problem is proved for deterministic pushdown automata and the main theorem leads to solution of a number of open problems in the theory of program schemes and in formal language theory.
Abstract: Decidability of the equivalence problem is proved for deterministic pushdown automata. A comparison algorithm for two automata is described. The main theorem leads to solution of a number of open problems in the theory of program schemes and in formal language theory.
11 citations
TL;DR: It is shown that synchronization dramatically enhances the power of pushdown automata, even under the severe restriction of the pushdown store to a counter making only one reversal, synchronized push down automata still recognize all recursively enumerable languages.
3 citations
25 Feb 1993
TL;DR: It is shown that two-way reversal-bounded pushdown automata over bounded languages (i.e., subsets of w 1 * ... w k * for some nonnull words w1 ..., wk) are equivalent to two- way reversal- bounded counter machines.
Abstract: It is known that two-way pushdown automata ate more powerful than two-way counter machines. The result is also true for the case when the pushdown store and counter are reversal-bounded. In contrast, we show that two-way reversal-bounded pushdown automata over bounded languages (i.e., subsets of w 1 * ... w k * for some nonnull words w1 ..., wk) are equivalent to two-way reversal-bounded counter machines. We also show that, unlike the unbounded input case, two-way reversal-bounded pushdown automata over bounded languages have decidable emptiness, equivalence and containment problems.
2 citations
TL;DR: It is shown that each 2-bounded language recognizing by a nonsensing multihead one-way deterministic pushdown automaton (1-DPDA) can be recognized by a sensing 3- head one- way deterministic finite automaton.
05 Dec 1993
TL;DR: In this paper, a new discrete recurrent model with discrete external stacks for learning context-free grammars (or pushdown automata) is described.
Abstract: In this paper, we describe a new discrete recurrent model with discrete external stacks for learning context-free grammars (or pushdown automata).