There is No Low Maximal D.C.E. Degree
M. M. Arslanov, S. Barry Cooper, Angsheng Li · Mathematical logic quarterly · 2000
We show that for any computably enumerable (c.e.) set A and any set L, if L is low and , then there is a c.e. splitting such that . In Particular, if L is low and n-c.e., then is n-c.e. and hence there is no low maximal n-c.e. degree.