Myhill isomorphism theorem
In computability theory the Myhill isomorphism theorem, named after John Myhill, provides a characterization for two numberings to induce the same notion of computability on a set. It is reminiscent of the Schröder–Bernstein theorem in set theory and has been called a constructive version of it.
Source: Wikipedia — Myhill isomorphism theorem (CC BY-SA 4.0)