2014/10/15 by Flood, Stephen, Towsner, Henry · 1 citation
#FOS: Mathematics #Logic (math.LO)
paper · doi:10.48550/arxiv.1410.4068
In this paper, we study Ramsey-type Konig's Lemma, written RWKL, using a technique introduced by Lerman, Solomon, and the second author. This technique uses iterated forcing to construct an omega-model satisfying one principle T1 but not another T2. The technique often allows one to translate a "one step" construction (building an instance of T2 along with a collection of solutions to each computable instance of T1) into an omega-model separation (building a computable instance of T2 together with a Turing ideal where T1 holds). We illustrate this translation by separating d-DNR from DNR (reproving a result of Ambos-Spies, Kjos-Hanssen, Lempp, and Slaman), and then apply this technique to separate RWKL from DNR (which has been shown separately by Bienvenu, Patey, and Schafer).