Restricted jump interpolation in the d.c.e. degrees
ANGSHENG LI · Mathematical Structures in Computer Science · 2006
We show that for any 2- computably enumerable Turing degree ${\bf l}$ , any computably enumerable degree ${\bf a}$ and any Turing degree ${\bf s}$ , if ${\bf l'=\boldsymbol{0}'}$ , ${\bf l<a}$ , ${\bf s\geq \boldsymbol{0}'}$ , and ${\bf s}$ is c.e. in ${\bf a}$ , then there is a 2-computably enumerable degree ${\bf x}$ with the following properties: ${\bf l<x