A reduction of the recursion scheme

1968 ◽  
Vol 32 (4) ◽  
pp. 505-508 ◽  
Author(s):  
M. D. Gladstone
Keyword(s):  
Recursive Functions ◽  
Standard Work ◽  
Recursion Scheme ◽  
Primitive Recursive

The class of primitive recursive functions may be defined as the closure of certain initial functions, namely the zero, successor and identity functions, under two schemes, namely composition (sometimes called “substitution”) and recursion. For a detailed definition the reader is referred to any standard work, for instance p. 219 of [2], by Kleene.

Simplifications of the recursion scheme

1971 ◽  
Vol 36 (4) ◽  
pp. 653-665 ◽  
Author(s):  
M. D. Gladstone
Keyword(s):  
Recursion Scheme ◽  
Projection Functions ◽  
Primitive Recursive

This paper resolves 3 problems left open by R. M. Robinson in [3].We recall that the set of primitive recursive functions is the closure under (i) substitution (or “composition”), and (ii) recursion, of the set P consisting of the zero, successor and projection functions (see any textbook, for instance p. 120 of [2]).

A Hierarchy on the Class of Primitive Recursive Ordinal Functions

1976 ◽  
Vol 28 (6) ◽  
pp. 1205-1209
Author(s):  
Stanley H. Stahl
Keyword(s):  
Natural Numbers ◽  
Recursive Functions ◽  
Set Functions ◽  
Primitive Recursive ◽  
Class Of Functions ◽  
Recursive Set

The class of primitive recursive ordinal functions (PR) has been studied recently by numerous recursion theorists and set theorists (see, for example, Platek [3] and Jensen-Karp [2]). These investigations have been part of an inquiry concerning a larger class of functions; in Platek's case, the class of ordinal recursive functions and in the case of Jensen and Karp, the class of primitive recursive set functions. In [4] I began to study PR in depth and this paper is a report on an attractive analogy between PR and its progenitor, the class of primitive recursive functions on the natural numbers (Prim. Rec).

A Macro Program for the Primitive Recursive Functions

1991 ◽  
Vol 37 (8) ◽  
pp. 121-124
Author(s):  
Hilbert Levitz ◽  
Warren Nichols ◽  
Robert F. Smith
Keyword(s):  
Recursive Functions ◽  
Primitive Recursive

The relation of A to Prov ˹A˺ in the Lindenbaum sentence algebra

1973 ◽  
Vol 38 (2) ◽  
pp. 295-298 ◽  
Author(s):  
C. F. Kent
Keyword(s):  
Boolean Algebra ◽  
Normal Forms ◽  
Order Relation ◽  
Mathematical Induction ◽  
Axiomatic Theory ◽  
Recursive Functions ◽  
Primitive Recursive

Let U be a consistent axiomatic theory containing Robinson's Q [TMRUT, p. 51]. In order for the results below to be of interest, U must be powerful enough to carry out certain arguments involving versions of the “derivability conditions,” DC(i) to DC(iii) below, of [HBGM, p. 285], [F60, Theorem 4.7], or [L55]. Thus it must contain, at least, mathematical induction for formulas whose prenex normal forms contain at most existential quantifiers. For convenience, U is assumed also to contain symbols for primitive recursive functions and relations, and their defining equations. One of these is used to form the standard provability predicate, Prov ˹A˺, “there exists a number which is the Gödel number of a proof of A.” Upper corners denote numerals for Gödel numbers for the enclosed sentences, and parentheses are often omitted in their presence.This paper contains some results concerning the relation between the sentence A, and the sentence Prov ˹A˺ in the Lindenbaum Sentence Algebra (LSA) for U, the Boolean algebra induced by the pre-order relation A ≤ B ⇔ ⊦A → B. Half of the answer is provided by a theorem of Löb [L55], which states that ⊦Prov ˹A˺ → A ⇔ ⊦A. Hence, in the presence of DC(iii), below, it is never true that Prov ˹A˺ < A in the LSA. However, there is a large and interesting set of sentences, denoted here by Γ, for which A < Prov ⌜A⌝.

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