I'm starting to dabble in language theory, regular expression & infinite words.
I'm not quite sure I completely get the meaning of this expression:
$(a + b)^\omega$
$^w$ meaning infinite repetition, I'm not positive it's standard syntaxe or just our class.
My main question is - do I have to "settle" on either a or b after some position in the infinite word? $abbbbaab^\omega$ would be fine but not $abbbbaa[ a | b]^\omega$ (e.g. I keep having either a or b infinitely)? My understanding is that an English translation would be "you must either have a, or b, at any given position indefinitely". So the + would be like a or condition, essentially.
Expending on that, then $((a+b)(c+d))^\omega$ would accept any alternating patter of (a or b)(c or d), e.g. things like acbcbcadad... but again wouldn't have to "settle" on either $(ac)^\omega$ or $(ad)^\omega$ or $(cc)^\omega$ etc...