Definition: The classes of languages accepted by k-alternating Turing machines, over all k≥ 0 and with initial state existential or universal. The bottom level (k=0) is the class P. The next level (k=1) comprises NP and co- NP.
Note: From Algorithms and Theory of Computation Handbook, page 29-20, Copyright © 1999 by CRC Press LLC. Appearing in the Dictionary of Computer Science, Engineering and Technology, Copyright © 2000 CRC Press LLC.
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Entry modified 17 December 2004.
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Cite this as:
Algorithms and Theory of Computation Handbook, CRC Press LLC, 1999, "polynomial hierarchy", in Dictionary of Algorithms and Data Structures [online], Vreda Pieterse and Paul E. Black, eds. 17 December 2004. (accessed TODAY) Available from: https://www.nist.gov/dads/HTML/polynomhier.html