Sunday, May 13, 2007

Deterministic Finite Automata (DFA)

DFAs are equivalent in computing power to NFAs (nondeterministic finite automata).On the other hand, DFAs are of strictly limited power in the languages they can recognize — many simple languages, including any problem that requires more than constant space to solve, cannot be recognized by a DFA.
The classical example of a simply described language that no DFA can recognize is the language consisting of strings of the form anbn — some finite number of a's, followed by an equal number of b's. It can be shown that no DFA can have enough states to recognize such a language.
See you later with our next post….

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