5 found
Order:
  1.  21
    Indestructible Weakly Compact Cardinals and the Necessity of Supercompactness for Certain Proof Schemata.J. D. Hamkins & A. W. Apter - 2001 - Mathematical Logic Quarterly 47 (4):563-572.
    We show that if the weak compactness of a cardinal is made indestructible by means of any preparatory forcing of a certain general type, including any forcing naively resembling the Laver preparation, then the cardinal was originally supercompact. We then apply this theorem to show that the hypothesis of supercompactness is necessary for certain proof schemata.
    Direct download  
     
    Export citation  
     
    Bookmark   7 citations  
  2.  38
    Infinite Time Turing Machines With Only One Tape.D. E. Seabold & J. D. Hamkins - 2001 - Mathematical Logic Quarterly 47 (2):271-287.
    Infinite time Turing machines with only one tape are in many respects fully as powerful as their multi-tape cousins. In particular, the two models of machine give rise to the same class of decidable sets, the same degree structure and, at least for partial functions f : ℝ → ℕ, the same class of computable functions. Nevertheless, there are infinite time computable functions f : ℝ → ℝ that are not one-tape computable, and so the two models of infinitary computation (...)
    Direct download  
     
    Export citation  
     
    Bookmark   6 citations  
  3.  9
    Andrkka, H., Givant, S., Mikulb, S., Ntmeti, I. and Simon, A.C. Butz, P. Johnstone, J. Gallier, J. D. Hamkins, B. Khoussaiuov, H. Lombardi & C. Raffalli - 1998 - Annals of Pure and Applied Logic 91 (1):271.
    No categories
    Direct download (2 more)  
     
    Export citation  
     
    Bookmark   5 citations  
  4. Pf= NPf almost everywhere.J. D. Hamkins & P. D. Welch - 2003 - Mathematical Logic Quarterly 49 (5):536-540.
    No categories
     
    Export citation  
     
    Bookmark  
  5.  58
    P^f NP^f for almost all f.J. D. Hamkins - 2003 - Mathematical Logic Quarterly 49 (5):536.
    We discuss the question of Ralf-Dieter Schindler whether for infinite time Turing machines Pf = NPf can be true for any function f from the reals into ω1. We show that “almost everywhere” the answer is negative.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark