×

zbMATH — the first resource for mathematics

A unique positive enumeration. (English) Zbl 0849.03035
Summary: We study the question about existence and the number of minimal positive elements in Rogers semilattices of equivalence classes of computable enumerations of families of recursively enumerable sets. We prove existence of some families with exactly one positive element that is not the smallest in the Rogers semilattice.

MSC:
03D45 Theory of numerations, effectively presented structures
PDF BibTeX XML Cite