15 citations · 26 across the 27 of their papers we have counts for
3 papers · 1 filter
Realizability Models Separating Various Fan Theorems
Robert S. Lubarsky, Michael Rathjen
We develop a realizability model in which the realizers are the reals not just Turing computable in a fixed real but rather the reals in a countable ideal of Turing degrees. This i…
On the Constructive Dedekind Reals
Robert Lubarsky, Michael Rathjen
In order to build the collection of Cauchy reals as a set in constructive set theory, the only Power Set-like principle needed is Exponentiation. In contrast, the proof that the De…
Ordinal notation systems corresponding to Friedman's linearized well-partial-orders with gap-condition
Michael Rathjen, Jeroen Van der Meeren, Andreas Weiermann
In this article we investigate whether the addition-free theta functions form a canonical notation system for the linear versions of Friedman's well-partial-orders with the so-call…