Reflection and forcing in E-recursion theory
E-recursive enumerability is compared via forcing to \(\Sigma_ 1\) definability. It is shown that for every countable E-closed ordinal \(\kappa\) there is a set of reals, X, so that \(L_{\kappa}[X]\) is the least E-closed structure over X.
scientific article; zbMATH DE number 3916253