Cheap and Secure Web Hosting Provider : See Now

# [Answers] Making a finite automata

, ,
Problem Detail:

How can I make a finite automaton which does not end in string ab.

With the alphabet a,b

I made 3 states. For the first one it is accepting states and thus accept the empty string.

So here is a table I made. State 1 is initial state

        input   goes to state input goes to state 

State 1

         b       1             a      2 

state 2

          b       3             a       2 

state 3

            b       3              a      3 

But will it work?

###### Asked By : Fernando Martinez

Here is your suggested automaton, if I understand your transitions correctly (initial state is 1)

This automaton will only accept $\epsilon$, and words consisting of a number of $b$'s

Hints to make one that accepts your language:

Make sure that it accepts $\epsilon, a, b$ and make sure that you "move away" from accepting states when seeing a $b$ after an $a$ (keep in mind that $aabb$ is also a string in the language, i.e the second $b$ should make the machine go to an accepting state).