Random non-cupping revisited


G. Barmpalias

Summary


We study the problem of cupping with random sets. Nies has shown that every random set below the halting problem has the strong random anticupping property via a promptly simple anticupping witness. We show that every set below the halting problem (not necessarily random) has the random anticupping property via a promptly simple anticupping witness. Moreover, we prove the following stronger statement: for every noncomputable Y below the halting problem there exists a promptly simple A such that if the join of it with a random is above Y then the random set is above A.