It is well-known that it is undecidable, given an NPDA whose stack makes only one reversal (or, equivalently, a linear CFG), whether it is unambiguous. It is also known that its unbounded ambiguity problem is undecidable . Here, we show that it is undecidable, given a nondeterministic counter automaton (NCA), whether it is unambiguous (resp., has… (More)
Figures and Tables
Sorry, we couldn't extract any figures or tables for this paper.