Highly Undecidable Problems For Infinite Computations

@article{Finkel2009HighlyUP,
  title={Highly Undecidable Problems For Infinite Computations},
  author={Olivier Finkel},
  journal={ArXiv},
  year={2009},
  volume={abs/0901.0373}
}
  • O. Finkel
  • Published 4 January 2009
  • Mathematics
  • ArXiv
We show that many classical decision problems about 1-counter omega-languages, context free omega-languages, or infinitary rational relations, are $\Pi_2^1$-complete, hence located at the second level of the analytical hierarchy, and "highly undecidable". In particular, the universality problem, the inclusion problem, the equivalence problem, the determinizability problem, the complementability problem, and the unambiguity problem are all $\Pi_2^1$-complete for context-free omega-languages or… 
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  • Mathematics
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