Switch to: References

Add citations

You must login to add citations.
  1. Interpretability in Robinson's Q.Fernando Ferreira & Gilda Ferreira - 2013 - Bulletin of Symbolic Logic 19 (3):289-317.
    Edward Nelson published in 1986 a book defending an extreme formalist view of mathematics according to which there is animpassable barrierin the totality of exponentiation. On the positive side, Nelson embarks on a program of investigating how much mathematics can be interpreted in Raphael Robinson's theory of arithmetic. In the shadow of this program, some very nice logical investigations and results were produced by a number of people, not only regarding what can be interpreted inbut also what cannot be so (...)
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   4 citations  
  • Harrington’s conservation theorem redone.Fernando Ferreira & Gilda Ferreira - 2008 - Archive for Mathematical Logic 47 (2):91-100.
    Leo Harrington showed that the second-order theory of arithmetic WKL 0 is ${\Pi^1_1}$ -conservative over the theory RCA 0. Harrington’s proof is model-theoretic, making use of a forcing argument. A purely proof-theoretic proof, avoiding forcing, has been eluding the efforts of researchers. In this short paper, we present a proof of Harrington’s result using a cut-elimination argument.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   1 citation