The Kraft--Barmpalias--Lewis-Pye lemma revisited
arXiv:2304.04852
Abstract
This note provides a simplified exposition of the proof of hierarchical Kraft lemma proven by Barmpalias and Lewis-Pye and its consequences for the oracle use in the Kučera--Gács theorem (saying that every sequence is Turing reducible to a random one).
(Added a small remark about non-binary case in v.2)