Definable hereditary families in the projective hierarchy
Barua, R. ; Srivatsa, V.
Fundamenta Mathematicae, Tome 141 (1992), p. 183-189 / Harvested from The Polish Digital Mathematics Library
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We show that if ℱ is a hereditary family of subsets of ωω satisfying certain definable conditions, then the Δ11 reals are precisely the reals α such that β:α∈Δ11(β)∉∈ℱ. This generalizes the results for measure and category. Appropriate generalization to the higher levels of the projective hierarchy is obtained under Projective Determinacy. Application of this result to the Q2n+1-encodable reals is also shown.

Publié le : 1992-01-01
EUDML-ID : urn:eudml:doc:211937 
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Barua, R.; Srivatsa, V. Definable hereditary families in the projective hierarchy. Fundamenta Mathematicae, Tome 141 (1992) pp. 183-189. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-fmv140i2p183bwm/

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