Journal of Symbolic Logic

Comparing DNR and WWKL

Klaus Ambos-Spies, Bjørn Kjos-Hanssen, Steffen Lempp, and Theodore A. Slaman

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In Reverse Mathematics, the axiom system DNR, asserting the existence of diagonally non-recursive functions, is strictly weaker than WWKL0 (weak weak König's Lemma).

Article information

J. Symbolic Logic, Volume 69, Issue 4 (2004), 1089-1104.

First available in Project Euclid: 2 December 2004

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Mathematical Reviews number (MathSciNet)

Zentralblatt MATH identifier

Primary: 03D28: Other Turing degree structures 03F35: Second- and higher-order arithmetic and fragments [See also 03B30]
Secondary: 03F60: Constructive and recursive analysis [See also 03B30, 03D45, 03D78, 26E40, 46S30, 47S30]

reverse mathematics diagonally non-recursive functions Turing degrees


Ambos-Spies, Klaus; Kjos-Hanssen, Bjørn; Lempp, Steffen; Slaman, Theodore A. Comparing DNR and WWKL. J. Symbolic Logic 69 (2004), no. 4, 1089--1104. doi:10.2178/jsl/1102022212.

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