Notre Dame Journal of Formal Logic
- Notre Dame J. Formal Logic
- Volume 56, Number 1 (2015), 61-79.
The Finitistic Consistency of Heck’s Predicative Fregean System
Luís Cruz-Filipe and Fernando Ferreira
Abstract
Frege’s theory is inconsistent (Russell’s paradox). However, the predicative version of Frege’s system is consistent. This was proved by Richard Heck in 1996 using a model-theoretic argument. In this paper, we give a finitistic proof of this consistency result. As a consequence, Heck’s predicative theory is rather weak (as was suspected). We also prove the finitistic consistency of the extension of Heck’s theory to -comprehension and of Heck’s ramified predicative second-order system.
Article information
Source
Notre Dame J. Formal Logic, Volume 56, Number 1 (2015), 61-79.
Dates
First available in Project Euclid: 24 March 2015
Permanent link to this document
https://projecteuclid.org/euclid.ndjfl/1427202974
Digital Object Identifier
doi:10.1215/00294527-2835110
Mathematical Reviews number (MathSciNet)
MR3326589
Zentralblatt MATH identifier
1356.03101
Subjects
Primary: 03F25: Relative consistency and interpretations 03F35: Second- and higher-order arithmetic and fragments [See also 03B30]
Secondary: 03B30: Foundations of classical theories (including reverse mathematics) [See also 03F35] 03F05: Cut-elimination and normal-form theorems 03A05: Philosophical and critical {For philosophy of mathematics, see also 00A30}
Keywords
Fregean arithmetic strict predicativity consistency
Citation
Cruz-Filipe, Luís; Ferreira, Fernando. The Finitistic Consistency of Heck’s Predicative Fregean System. Notre Dame J. Formal Logic 56 (2015), no. 1, 61--79. doi:10.1215/00294527-2835110. https://projecteuclid.org/euclid.ndjfl/1427202974


