I am trying to clear something that seems to be a little misleading for me.
I know the language over {a,b} consisting of all words containing the same number of occurrences of
the symbol a as of the symbol b is not regular.
I know that the language L over {a,b} consisting of all words containing
the same number of occurrences of ab as a substring as occurrences of ba as a substring
actually is regular.
What would be the best way to prove this? by finding a finite automaton that accepts this language?
