|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|4661672||1344855||2015||12 صفحه PDF||سفارش دهید||دانلود کنید|
We study the relationship among members of Π10 classes, thin Π10 classes, their Cantor–Bendixson ranks and their Turing degrees; in particular, we show that any nonzero Δ20 degree contains a member of rank α for any computable ordinal α . Furthermore we observe that the degrees containing members of thin Π10 classes are not closed under join.
Journal: Annals of Pure and Applied Logic - Volume 166, Issues 7–8, July–August 2015, Pages 755–766