Lowness for isomorphism, countable ideals, and computable traceability
Johanna N. Y. Franklin, Reed Solomon · Mathematical logic quarterly · 2020
Abstract We show that every countable ideal of degrees that are low for isomorphism is contained in a principal ideal of degrees that are low for isomorphism by adapting an exact pair construction. We further show that within the hyperimmune free degrees, lowness for isomorphism is entirely independent of computable traceability.