nondeterministic finite state machine


Definition: A finite state machine whose transition function maps inputs symbols and states to a (possibly empty) set of next states. The transition function also may map the null symbol (no input symbol needed) and states to next states.

Also known as NFA, nondeterministic finite automaton.

See also deterministic finite state machine.

Note: Any such machine may be converted to a deterministic finite state machine, although the number of states may increase by an exponential amount.

Thanks to Thorsten Jens ( and Yaacov Yesha ( for correcting this entry. 17 January 2001.

Author: PEB

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Entry modified 17 December 2004.
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Cite this as:
Paul E. Black, "nondeterministic finite state machine", in Dictionary of Algorithms and Data Structures [online], Paul E. Black, ed. 17 December 2004. (accessed TODAY) Available from: