Π10 classes and minimal degrees
Marcia J. Groszek, Theodore A. Slaman · Annals of Pure and Applied Logic · 1997
Theorem. There is a non-empty Π10 class of reals, each of which computes a real of minimal (Turing) degree. Corollary. WKL ⊢ “there is a minimal Turing degree”. This answers a question of H. Friedman and S. Simpson.