LEXICAL ANALYSIS
REGULAR EXPRESSIONS AND FINITE AUTOMATA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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YES
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NO
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Either A or B
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None of the above
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Detailed explanation-1: -The transition from a state can be to multiple next states for each input symbol. Hence it is called non-deterministic. Empty string transitions are not seen in DFA.
Detailed explanation-2: -A incomplete DFA (where the null state is omitted) or a complete DFA (where the null state is present as an inescapable state).
Detailed explanation-3: -An NFA with null transition is allowed to make transition not only on input from the alphabet but also with null input, i.e. without any input symbol. This transition without input is called null transition.
Detailed explanation-4: -This DFA does not accept any string because it has no accepting state. Thus the language it accepts is the empty set . This DFA has a cycle: 1-2-1 and it can go through this cycle any number of times by reading substring ab repeatedly.