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Index sets of finite classes of recursively enumerable sets

Published online by Cambridge University Press:  12 March 2014

Louise Hay*
Affiliation:
University of Illinois at Chicago Circle Mount Holyoke College

Extract

Let q0, q1,… be a standard enumeration of all partial recursive functions of one variable. For each i, let wi = range qi and for any recursively enumerable (r.e.) set α, let θα = {n | wn = α}. If A is a class of r.e. sets, let θA = the index set of A = {n | wn ∈ A}. It is the purpose of this paper to classify the possible recursive isomorphism types of index sets of finite classes of r.e. sets. The main theorem will also provide an answer to the question left open in [2] concerning the possible double isomorphism types of pairs (θα, θβ) where α ⊂ β.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1969

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References

[1]Dekker, J. C. E. and Myhill, J., Some theorems on classes of recursively enumerable sets, Transactions of the American Mathematical Society, vol. 89 (1958), pp. 2559.CrossRefGoogle Scholar
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