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Page 4578 of Mathematical Reviews Vol. , Issue 98G [page]

1998 Mathematical Reviews  
in pushdown automata.  ...  The author introduces a notion of y- similarity (a quantitative degree which can be seen as the average value of the Hamming-distances of the output sequences of the automata A; and A> for the same input  ... 

Nondeterministic Tree Width of Regular Languages [chapter]

Cezar Câmpeanu, Kai Salomaa
2015 Lecture Notes in Computer Science  
Nondeterminism plays a fundamental role in the theory of computation. • For some machine models, nondeterminism enhances the computational power of the model (pushdown automata), while for others it  ...  • For some machine models, nondeterminism enhances the computational power of the model (pushdown automata), while for others it does not (Turing machines, finite automata).  ... 
doi:10.1007/978-3-319-19225-3_4 fatcat:bidsr5wxpjcqfhhkd3g5k2dksy

Page 2885 of Mathematical Reviews Vol. , Issue 2003d [page]

2003 Mathematical Reviews  
Among the topics considered are limited nondeterminism, limited ambiguity, multiple initial states, two-way automata, pushdown automata with limited nondeterminism and ambiguity, the size of grammars for  ...  For example, in the case of finite automata, a reasonable complexity measure is the number of states of the automata.  ... 

Page 1895 of Mathematical Reviews Vol. 57, Issue 5 [page]

1979 Mathematical Reviews  
>) where n is the number of nodes in T, whereas O(n?) steps are sufficient for trees T with a fixed degree bound.  ...  For example, multihead 2-way pushdown automata accept exactly those lan- guages accepted in polynomial time by Turing machines. It is  ... 

Measures of nondeterminism for pushdown automata

Kai Salomaa, Sheng Yu
1994 Journal of computer and system sciences (Print)  
Inform. 4 (1981), 401-418) introduced two measures of nondeterminism for pushdown automata and showed interestingly that the second measure, which we refer to as the depth measure, yields an infinite hierarchy  ...  In this paper, using a pumping result for deterministic context-free languages we give a new proof for the strictness of the depth hierarchy.  ...  Vermeir and Savitch introduced in [8] two measures of nondeterminism for pushdown automata.  ... 
doi:10.1016/s0022-0000(05)80054-6 fatcat:mueexpgd3jfoxax2rcuayvau6u

Pumping and pushdown machines

Kai Salomaa, D. Wood, Sheng Yu
1994 RAIRO - Theoretical Informatics and Applications  
Two measurements of nondeterminism for pushdown automata were introduced by Vermeir and Savitch [10] and investigated by Salomaa and Yu [7, 9] .  ...  language has nondeterminism-degree complexity N if there is a pushdown machine M such that L -L (M) and the nondeterminism degree of M is TV.  ... 
doi:10.1051/ita/1994283-402211 fatcat:7pffmzqjivfxfdyuf6stvatoom

Page 6402 of Mathematical Reviews Vol. , Issue 92k [page]

1992 Mathematical Reviews  
Summary: “We define a number of complexity classes by modified pushdown automata.  ...  These modifications are obtained through several restrictions on the way in which such a machine can access its input, or make use of its pushdown store or of nondeterminism.  ... 

Page 6991 of Mathematical Reviews Vol. , Issue 96k [page]

1996 Mathematical Reviews  
{For the entire collection see MR 96j:68010.} 96k:68120 68Q50 68Q10 68Q60 68Q68 68R10 Caucal, Didier (F-RENNB-II; Rennes) Bisimulation of context-free grammars and of pushdown automata.  ...  “Then we show that the rational restrictions of pushdown tran- sition graphs are exactly and effectively the regular graphs of finite degree.  ... 

Regulated nondeterminism in pushdown automata

Martin Kutrib, Andreas Malcher, Larissa Werlein
2009 Theoretical Computer Science  
A generalization of pushdown automata towards regulated nondeterminism is studied.  ...  The main goal of this paper is to investigate pushdown automata with regulated nondeterminism. The use of transition rules is controlled in a weak sense.  ...  Acknowledgments We would like to thank Jürgen Dassow for his suggestion to consider this generalization of context-dependent nondeterminism.  ... 
doi:10.1016/j.tcs.2009.06.002 fatcat:n2mpe347ajalriszatcuqebxd4

Simulation of Two-Way Pushdown Automata Revisited

Robert Glück
2013 Electronic Proceedings in Theoretical Computer Science  
The simulation is then extended to 2-way nondeterministic pushdown automata (2NPDA) to provide for a cubic-time recognition of context-free languages.  ...  The time required to run the final construction depends on the degree of nondeterminism. The key mechanism that enables the polynomial-time simulations is the sharing of computations by memoization.  ...  Jones for pointing the author to Cook's construction, and to Akihiko Takano for providing the author with excellent working conditions at the National Institute of Informatics, Tokyo.  ... 
doi:10.4204/eptcs.129.15 fatcat:mtosvaxch5c3jbhzzzltqvb5qe

Computations and Interaction [chapter]

Jos C. M. Baeten, Bas Luttik, Paul van Tilburg
2011 Lecture Notes in Computer Science  
We enhance the notion of a computation of the classical theory of computing with the notion of interaction.  ...  In this way, we enhance a Turing machine as a model of computation to a Reactive Turing Machine that is an abstract model of a computer as it is used nowadays, always interacting with the user and the  ...  In automata theory, every silent step τ and all nondeterminism can be removed from a finite automaton.  ... 
doi:10.1007/978-3-642-19056-8_3 fatcat:vytdx4nu75bk3ab2q2knslnejy

Page 3429 of Mathematical Reviews Vol. , Issue 89F [page]

1989 Mathematical Reviews  
Summary: “The equivalence problem for deterministic real-time pushdown automata is shown to be decidable.  ...  Equivalence is also de- cidable for two deterministic pushdown automata one of which is real-time.” 89f:68020 68Q05 11Y16 12D99 58C30 65HO0S Smale, Steve (1-CA) On the topology of algorithms. I. J.  ... 

Measuring nondeterminism in pushdown automata

Jonathan Goldstine, Hing Leung, Detlef Wotschke
2005 Journal of computer and system sciences (Print)  
When this quantity is unbounded, the rate at which it grows as the length of the string increases serves as a measure of the pushdown automaton's "rate of consumption" of nondeterminism.  ...  The amount of nondeterminism that a pushdown automaton requires to recognize an input string can be measured by the minimum number of guesses that it must make to accept the string, where guesses are measured  ...  Acknowledgments We are grateful to Christian Herzog for pointing out that the computations of an arbitrary PDA satisfy the pumping lemma for deterministic CFLs, and that this fact could be used to simplify  ... 
doi:10.1016/j.jcss.2005.04.001 fatcat:nnyckpydprfdxaunf4svgmukhe

Turing Meets Milner [chapter]

Jos C. M. Baeten, Bas Luttik, Paul van Tilburg
2012 Lecture Notes in Computer Science  
We enhance the notion of a computation of the classical theory of computing with the notion of interaction from concurrency theory.  ...  In this way, we enhance a Turing machine as a model of computation to a Reactive Turing Machine that is an abstract model of a computer as it is used nowadays, always interacting with the user and the  ...  In automata theory, every silent step τ and all nondeterminism can be removed from a finite automaton.  ... 
doi:10.1007/978-3-642-32940-1_1 fatcat:57cl6kqasvgbbi454em77i46tq

Measuring nondeterminism in pushdown automata [chapter]

Jonathan Goldstine, Hing Leung, Detlef Wotschke
1997 Lecture Notes in Computer Science  
When this quantity is unbounded, the rate at which it grows as the length of the string increases serves as a measure of the pushdown automaton's "rate of consumption" of nondeterminism.  ...  The amount of nondeterminism that a pushdown automaton requires to recognize an input string can be measured by the minimum number of guesses that it must make to accept the string, where guesses are measured  ...  Acknowledgments We are grateful to Christian Herzog for pointing out that the computations of an arbitrary PDA satisfy the pumping lemma for deterministic CFLs, and that this fact could be used to simplify  ... 
doi:10.1007/bfb0023467 fatcat:tig2fwofwjgo7eqg4lxec55jgm
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