ABSTRACT
We isolate a fact which holds for various degree structures arising from recursion theory and complexity theory and makes it possible to prove the undecidability of their theories in a more uniform way than in the original proofs, namely by interpreting the lattice of Σ k 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429187490/96848216-4cb0-482d-8de8-074974faecad/content/eq5840.tif"/> -sets for some k.
Dedicated to Kena Prosper
