I understand the meaning of epsilon transitions, but could someone give example where epsilon transition becomes handy?
Examples of epsilon transitions
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computer-science
automata
1 Answers
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Epsilon transitions come in handy to `chain' languages.
For example: to construct the kleene closure of a language, one connects the accepting states to a new starting state with epsilon transitions and one connects this new starting state with the old starting state with an epsilon transition.
This construction is probably a lot harder when one is not allowed to use epsilon transitions.
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0Or maybe to make a simpler example: You have a machine that accepts language $A$ and a machine that accepts language $B$, and you want to make a machine that accepts language $AB$. With $\epsilon$-transitions it's easy: Just attach the final states of $A$ to the start start of $B$ with an $\epsilon$-transition, and you are done. – 2012-09-01
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0@MJD can't forget to remove the accepting states from $A$ though! – 2012-09-01
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0In the same vein, $\epsilon$-transitions provide a simple proof that the union of, say, regular languages is regular. – 2012-09-02