The Π₃-theory of the Σ⁰₂-enumeration degrees is undecidable
Kent, Thomas F.
J. Symbolic Logic, Tome 71 (2006) no. 1, p. 1284-1302 / Harvested from Project Euclid
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We show that in the language of {≤}, the Π₃-fragment of the first order theory of the Σ⁰₂-enumeration degrees is undecidable. We then extend this result to show that the Π₃-theory of any substructure of the enumeration degrees which contains the Δ⁰₂-degrees is undecidable.
Publié le : 2006-12-14
Classification:  
@article{1164060455,
     author = {Kent, Thomas F.},
     title = {The P3-theory of the S02-enumeration degrees is undecidable},
     journal = {J. Symbolic Logic},
     volume = {71},
     number = {1},
     year = {2006},
     pages = { 1284-1302},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1164060455}
}

Kent, Thomas F. The Π₃-theory of the Σ⁰₂-enumeration degrees is undecidable. J. Symbolic Logic, Tome 71 (2006) no. 1, pp.  1284-1302. http://gdmltest.u-ga.fr/item/1164060455/