2 problems

Let $\Sigma$ be a finite alphabet, and let an omega-power of a finitary language $L\subseteq\Sigma^*$ be the set $L^\omega$ of infinite concatenations of words from $L$. Let…

Conjecture on Borel ranks of one-counter-automaton omega-powers. There exist $\omega$-powers of languages accepted by $1$-counter automata whose Borel ranks reach ordinals up to…