Elementary theories for Rogers semilattices. (Russian, English) Zbl 1106.03041
Algebra Logika 44, No. 3, 261-268 (2005); translation in Algebra Logic 44, No. 3, 143-147 (2005).
Summary: It is proved that for every level of the arithmetical hierarchy there exist infinitely many families of sets with pairwise non-elementarily equivalent Rogers semilattices.
MSC:
| 03D45 | Theory of numerations, effectively presented structures |
