Abstract

With each of the classical tree-like forcings adjoining a new real, one can associate a -ideal on the reals in a natural way. For example, the ideal s 0 of Marczewski null sets corresponds to Sacks forcingS, while the ideal r 0 of nowhere Ramsey sets corre- sponds to Mathias forcing R. We show (in ZFC) that none of these ideals is included in any of the others. We also discuss Mycielski's ideal P2, and start an investigation of the covering numbers of these ideals.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call