Deciding the First Levels of the Modal mu Alternation Hierarchy by Formula Construction
نویسندگان
چکیده
We construct, for any sentence Ψ of the modal μ calculus (Lμ), a derived sentence ΨML in the modal fragment ML of Lμ and a sentence ΨΠ μ 1 in the fragment Πμ1 of Lμ without least fixpoints such that Ψ is equivalent to a formula in ML or Πμ1 if and only if it is equivalent to ΨML or ΨΠ μ
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