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Classes with Rogers one-element semilattice. (English. Russian original) Zbl 0903.03025
Algebra Logika 37, No. 1, 36-62 (1998); translation in Algebra Logic 37, No. 1, 21-34 (1998).
The main results of the article are as follows: an algorithmic description is given of classes of general recursive functions having a Rogers one-element semilattice; it is also shown that there exists a class of recursively enumerable sets which is not a topological $$T_1$$-space under the Baire topology, but its Rogers semilattice is a singleton.
##### MSC:
 03D25 Recursively (computably) enumerable sets and degrees 03D20 Recursive functions and relations, subrecursive hierarchies
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