Self Doubt

Question

 

Convert DFA to regular expression 

Comments

Convert it to min-DFA, which will come as above, and then it can easily be converted to regular expression

Answer 1

(bb)*a(aa)* + a(ba)*

Comments

How do you get this regular expression?

$ba$ is not generated by regular expression but it is accepted by the given DFA.

Answer 2

(a+b)*a

if we create an nfa of this then there will be 2 states since we need least input to reach final state is a,we can give a self loop at q0 for a or b and to reach q1 state(final state) we can give input a

Comments

Exactly my point

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Regular expressions are only made to accept at finite automata they are not made to see what language is accepted by them

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no regular expression are not meant to accept languages. They generate languages.

Automata are machines which generates languages.

A language can have many DFAs but only one unique minimal DFA. Similarly a regular language will have many regular expressions.

$(a+b)^*a$ is wrong because it generates string not in the language of given DFA.