PCTL Satisfiability for Infinite Binary Trees
摘要
We show that the problem whether a given PCTL formula has an infinite binary tree model where all transition probabilities are equal to 1/2 is highly undecidable (i.e., beyond the arithmetical hierarchy). This result holds even for the PCTL fragment where the set of modal connectives is restricted to the \(\textbf{F}\) and \(\textbf{G}\) operators, and even under the assumption that the PCTL formula on input is either unsatisfiable or it has a model with the aforementioned structure.