9 found
Order:
  1.  18
    Chris Ash, Julia Knight, Mark Manasse, and Theodore Slaman. Generic Copies of Countable Structures. Annals of Pure and Applied Logic, Vol. 42 , Pp. 195–205. [REVIEW]Ivan N. Soskov - 1993 - Journal of Symbolic Logic 58 (3):1078-1079.
  2.  3
    The Jump Operator on the Ω-Enumeration Degrees.Hristo Ganchev & Ivan N. Soskov - 2009 - Annals of Pure and Applied Logic 160 (3):289-301.
    The jump operator on the ω-enumeration degrees was introduced in [I.N. Soskov, The ω-enumeration degrees, J. Logic Computat. 17 1193–1214]. In the present paper we prove a jump inversion theorem which allows us to show that the enumeration degrees are first order definable in the structure of the ω-enumeration degrees augmented by the jump operator. Further on we show that the groups of the automorphisms of and of the enumeration degrees are isomorphic. In the second part of the paper we (...)
    Direct download (4 more)  
     
    Export citation  
     
    Bookmark   4 citations  
  3.  3
    Intrinsically Hyperarithmetical Sets.Ivan N. Soskov - 1996 - Mathematical Logic Quarterly 42 (1):469-480.
    The main result proved in the paper is that on every recursive structure the intrinsically hyperarithmetical sets coincide with the relatively intrinsically hyperarithmetical sets. As a side effect of the proof an effective version of the Kueker's theorem on definability by means of infinitary formulas is obtained.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   8 citations  
  4.  7
    Intrinsically II 11 Relations.Ivan N. Soskov - 1996 - Mathematical Logic Quarterly 42 (1):109-126.
    An external characterization of the inductive sets on countable abstract structures is presented. The main result is an abstract version of the classical Suslin-Kleene characterization of the hyperarithmetical sets.
    Direct download (3 more)  
     
    Export citation  
     
    Bookmark   2 citations  
  5.  16
    Second Order Definability Via Enumerations.Ivan N. Soskov - 1991 - Zeitschrift fur mathematische Logik und Grundlagen der Mathematik 37 (2-4):45-54.
  6.  17
    Computability by Means of Effectively Definable Schemes and Definability Via Enumerations.Ivan N. Soskov - 1990 - Archive for Mathematical Logic 29 (3):187-200.
  7.  4
    Definability Via Enumerations.Ivan N. Soskov - 1989 - Journal of Symbolic Logic 54 (2):428-440.
  8.  5
    Review: Chris Ash, Julia Knight, Mark Manasse, Theodore Slaman, Generic Copies of Countable Structures. [REVIEW]Ivan N. Soskov - 1993 - Journal of Symbolic Logic 58 (3):1078-1079.
  9.  1
    Second Order Definability Via Enumerations.Ivan N. Soskov - 1991 - Mathematical Logic Quarterly 37 (2‐4):45-54.