Recursive Fibers of Rst Isols
نویسنده
چکیده
Motivated by a conjecture of Ellentuck concerning fibers f^x(C), f recursive and C an element of one of Barback's "tame models" (Tame models in the isols, Houston J. Math. 12 (1986), 163-175), we study such fibers in the more general context of Nerode semirings. The principal results are that (1) all existentially complete Nerode semirings meet all of their recursive fibers, and (2) not all Nerode semirings meet all of their recursive fibers.
منابع مشابه
Two Notes on Recursive Functions
Introduction. The theory of regressive isols was introduced by J. C. E. Dekker in [7]. The results that we wish to present in this paper belong to this theory and is a continuation of some of our studies in [1], [3] and [4]. We will assume that the reader is familiar with the terminology and some of the main results of the papers listed as references. We let E denote the collection of all nonne...
متن کاملHereditarily Odd–even and Combinatorial Isols
In this paper we study some of the arithmetic structure that is found in a special kind of semi-ring in the isols. These are the semi-rings [D(Y ),+, ·] that were introduced by J.C.E. Dekker, and that were later shown by E. Ellentuck to model the true universal recursive statements of arithmetic when Y is a regressive isol and is hyper-torre (= hereditarily odd-even = HOE). When Y is regressive...
متن کاملOn the Minimality of Tame Models in the Isols
Based on the work of Hirschfeld, it is known that there is a close connection between models for the n°j fragment of arithmetic and homomorphic images of the semiring of recursive functions. This fragment of arithmetic includes most of the familiar results of classical number theory. There is a realization of this fragment in the isols in systems called tame models. In this paper a new proof is...
متن کاملIncomplete self-orthogonal latin squares ISOLS(6m + 6, 2m) exist for all m
Heinrich, K., L. Wu and L. Zhu, Incomplete self-orthogonal latin squares ISOLS(6m + 6, 2m) exist fo all m, Discrete Mathematics 87 (1991) 281-290. An incomplete self-orthogonal latin square of order v with an empty subarray of order n, an ISOLS(v, n) can exist only if v 2 3n + 1. We show that an ISOLS(6m + 6, 2m) exists for all values of m and thus only the existence of an ISOLS(6m + 2,2m), m 2...
متن کاملMore About Recursive Structures: Descriptive Complexity and Zero-One Laws
This paper continues our work on innnite, recursive structures. We investigate the descriptive complexity of several logics over recursive structures, including rst-order, second-order, and xpoint logic, exhibiting connections between expressibility of a property and its computational complexity. We then address 0{1 laws, proposing a version that applies to recursive structures, and using it to...
متن کامل