Contents: (Math. Log. Quart. 2/2019)
Mathematical logic quarterly · 2019
A variant of Shelah's characterization of Strong Chang's Conjecture Shelah considered a certain version of Strong Chang's Conjecture which we denote SCC cof , and proved that it is equivalent to several statements, including the assertion that Namba forcing is semiproper.We introduce an apparently weaker version, denoted SCC split , and prove an analogous characterization of it.In particular, SCC split is equivalent to the assertion that the the Friedman-Krueger poset is semiproper.This strengthens and sharpens results by Cox and sheds some light on problems posed by Usuba, Torres-Perez and Wu.