DFM symbol a occurs twice

Question

Let the L language over the alphabet {a, b, c} consist exactly of all words in which the symbol a occurs at least twice. Draw a diagram of the deteminist state-finite automaton accepting L and provide a regular expression denoting this language.

Hello, Can you tell if the automaton attached by me is correct?

Best Regards !

https://drive.google.com/file/d/1ycnUliTY6e-Xl0f-xxqKKvASzgyo6QCZ/view?usp=sharing

Wuestenfux · Accepted Answer · 2019-02-17T18:57:08.743

1

Welcome to MSE! The automaton accepts words of the form $uava$, where $u,v$ are words over $\{b,c\}$. But you want words of the form $uavaw$, where $u,v,w$ are words over $\{b,c\}$.

Added: In the final state you need a loop with $b$ and $c$.

edited Feb 17 '19 at 18:57

answered Feb 15 '19 at 06:36

Wuestenfux

20,964

I thought that this automata was well written. How should it look like? – Mr. Pat Feb 17 '19 at 15:10
Yes! I forgot, now agrees thanks! – Mr. Pat Feb 18 '19 at 15:53

DFM symbol a occurs twice

1 Answers1