On the jumps of the degrees below an r.e. degree
David Belanger, Richard A. Shore, Ithaca Ny · 2015
A perhaps plausible conjecture about distinguishing among some r.e. degrees based on the jumps of degrees below them would prove the rigidity of the r.e. degrees. We show that the conjecture is false by exhibiting, for every c r.e. in and above 0 0 , distinct r.e. degrees a and b, each with jump c, such that the classes of the jumps of degrees below a and below b are the same.