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TCS
2012
12 years 7 days ago
Improved simulation of nondeterministic Turing machines
Abstract. The standard simulation of a nondeterministic Turing machine (NTM) by a deterministic one essentially searches a large boundeddegree graph whose size is exponential in th...
Subrahmanyam Kalyanasundaram, Richard J. Lipton, K...
TCS
2010
12 years 11 months ago
Non-confluence in divisionless P systems with active membranes
We describe a solution to the SAT problem via non-confluent P systems with active membranes, without using membrane division rules. Furthermore, we provide an algorithm for simula...
Antonio E. Porreca, Giancarlo Mauri, Claudio Zandr...
STACS
1999
Springer
13 years 9 months ago
A Logical Characterisation of Linear Time on Nondeterministic Turing Machines
The paper gives a logical characterisation of the class NTIME(n) of problems that can be solved on a nondeterministic Turing machine in linear time. It is shown that a set L of str...
Clemens Lautemann, Nicole Schweikardt, Thomas Schw...