Computable isomorphism


In computability theory two sets of natural numbers are computably isomorphic or recursively isomorphic if there exists a total computable and bijective function such that the image of restricted to equals, i.e..
Further, two numberings and are called computably isomorphic if there exists a computable bijection so that. Computably isomorphic numberings induce the same notion of computability on a set.

Theorems

By the Myhill isomorphism theorem, the relation of computably isomorphic coincides with the relation of mutual one-one reducibility.