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Fixed points of jump preserving automorphisms of degrees

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Abstract

It is shown that any jump preserving order automorphismF of the degrees of unsolvability must satisfyF(c) = c for all degreesc≧0 (4). The proof uses a result on initial segments of degrees in combination with an iteration of the Friedberg completeness criterion.

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References

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Authors and Affiliations

  1. University of Illinois at Urbana-Champaign, USA

    Carl G. Jockusch & Robert M. Solovay

  2. I.B.M. T. J. Watson Research Center, USA

    Carl G. Jockusch & Robert M. Solovay

Authors
  1. Carl G. Jockusch
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  2. Robert M. Solovay
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Additional information

This work was partially supported by NSF Grant MPS 74-07499 at the University of Illinois at Urbana-Champaign.

This work was partially supported by NSF Grant GP 38753X at the University of California, Berkeley.

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Jockusch, C.G., Solovay, R.M. Fixed points of jump preserving automorphisms of degrees. Israel J. Math. 26, 91–94 (1977). https://doi.org/10.1007/BF03007659

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  • DOI: https://doi.org/10.1007/BF03007659

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