Take a look at the following expression:
Or, to put it simply: the words in the language, have repeating parts consisting of, some A's followed by a single B.
There are TWO school of thoughts about this, which can be broken down, by this question:
Is the word ABAAB, a part of the language?
I say, that it's not, as each repeating part must have the same number (n) of A's in it.
Others claim that each repeating part can have it's own number of A's
I am willing to concede, that had the expression used +, instead of n>0, then each repeat, could have been different (although, I don't like this concession).
The question is: Is the variable in the inner part "locked", or can that variable have different values in each iteration of the part.
What I'd like, is a credible source that I can point to that explains which way is correct.
(ps, if my understanding of the expression is the correct one, it means the language is not regular; if I am wrong, it is regular).
Thank you all.