2010 seminar talk: Divorces in the PFA family
Talk held by Miguel Angel Mota (KGRC) at the KGRC seminar on 2010-04-15.
Abstract
Using some variants of weak club guessing we separate some fragments of the proper forcing axiom: we show that for every two indecomposable ordinals α < β, the forcing axiom for the class of all the β-proper posets does not imply the bounded forcing axiom for the class of all the α-proper posets. This is joint work with S. Friedman and M. Sabok.