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As per the question, can a pushdown automata have zero final states?

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2 回答 2

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Yep! There are many different definitions of PDAs, but usually the definition says that a PDA has a set of accepting states, which must be a subset of the set of all states in the PDA. The empty set is a valid set, so the PDA doesn't necessarily ever have to accept. This is how it's possible to build a PDA for the empty language, for example, which is known to be context-free.

Hope this helps!

于 2013-03-30T21:42:56.513 回答
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Some forms of push-down automaton accept by halting with an empty stack at end of input. For this form, there is no such thing as a final state.

于 2013-11-08T01:16:12.240 回答