11 Basis theorems

In earlier chapters we have seen examples of uncountable sets of reals (e.g. image and certain image-sets) that contain perfect subsets. In this chapter we study basis theorems for uncountable sets of reals as well as basis properties of perfect sets.

11.1 A basis theorem for image-sets of reals

11.1.1 Friedman’s conjecture

Friedman [29] conjectured that every uncountable -set of reals has a member in each hyperdegree greater than or equal to the ...

Get Recursion Theory now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.