Add to ORKGThis paper deals with: (i) the theory which results from by restricting induction on the natural numbers to formulas which are positive in the fixed point constants, (ii) the theory BON(μ) plus various forms of positive induction, and (iii) a subtheory of Peano arithmetic with ordinals in which induction on the natural numbers is restricted to formulas which are Σ in the ordinals. We show that these systems have proof-theoretic strength φω
In this paper we prove a boundedness theorem in the theory ID1(W). This answers a question asked by ...
AbstractWe characterize the proof-theoretic strength of systems of explicit mathematics with a gener...
AbstractFeferman, S. and G. Jäger, Systems of explicit mathematics with non-constructive μ-operator....
This paper deals with: (i) the theory ID*# which results ÎD1 from by restricting induction on the na...
AbstractJäger, G., Fixed points in Peano arithmetic with ordinals, Annals of Pure and Applied Logic ...
AbstractJäger, G., Fixed points in Peano arithmetic with ordinals, Annals of Pure and Applied Logic ...
This paper presents several proof-theoretic results concerning weak fixed point theories over second...
AbstractThis paper deals with the proof theory of first-order applicative theories with non-construc...
In this paper we give an overview of an essential part of a $Pi^0_1$ ordinal analysis of Peano Arith...
The starting point of this article is an old question asked by Feferman in his paper on Hancock's co...
AbstractWhen a structure or class of structures admits an unbounded induction, we can do arithmetic ...
AbstractWe investigate the “mathematical” strength of the theory I∄∗2. In particular we prove the qu...
An approach to ordinal analysis is presented which is finitary, but highlights the semantic content ...
We have still to consider the extension of the methods of number theory to infinite ordinals—or to t...
Ordinal notations and provability of well-foundedness have been a central tool in the study of the c...
In this paper we prove a boundedness theorem in the theory ID1(W). This answers a question asked by ...
AbstractWe characterize the proof-theoretic strength of systems of explicit mathematics with a gener...
AbstractFeferman, S. and G. Jäger, Systems of explicit mathematics with non-constructive μ-operator....
This paper deals with: (i) the theory ID*# which results ÎD1 from by restricting induction on the na...
AbstractJäger, G., Fixed points in Peano arithmetic with ordinals, Annals of Pure and Applied Logic ...
AbstractJäger, G., Fixed points in Peano arithmetic with ordinals, Annals of Pure and Applied Logic ...
This paper presents several proof-theoretic results concerning weak fixed point theories over second...
AbstractThis paper deals with the proof theory of first-order applicative theories with non-construc...
In this paper we give an overview of an essential part of a $Pi^0_1$ ordinal analysis of Peano Arith...
The starting point of this article is an old question asked by Feferman in his paper on Hancock's co...
AbstractWhen a structure or class of structures admits an unbounded induction, we can do arithmetic ...
AbstractWe investigate the “mathematical” strength of the theory I∄∗2. In particular we prove the qu...
An approach to ordinal analysis is presented which is finitary, but highlights the semantic content ...
We have still to consider the extension of the methods of number theory to infinite ordinals—or to t...
Ordinal notations and provability of well-foundedness have been a central tool in the study of the c...
In this paper we prove a boundedness theorem in the theory ID1(W). This answers a question asked by ...
AbstractWe characterize the proof-theoretic strength of systems of explicit mathematics with a gener...
AbstractFeferman, S. and G. Jäger, Systems of explicit mathematics with non-constructive μ-operator....