Conservations of first-order reflections

Abstract

The set theory KP${\Pi }_{N+1}$ for ${\Pi }_{N+1}$-reflecting universes is shown to be ${\Pi }_{N+1}$-conservative over iterations of ${\Pi }_N$-recursively Mahlo operations for each $N\ge 2$.

References in corpus (2)

• Iterating the recursively Mahlo operations
• Lifting up the proof theory to the countables : Zermelo-Fraenkel set theory