Forcing a set model of + Harrington's Principle
Forcing a set model of + Harrington's Principle
Let denote third order arithmetic. Let Harrington's Principle, , denote the statement that there is a real x such that every x āadmissible ordinal is a cardinal in . In this paper, assuming there exists a remarkable cardinal with a weakly inaccessible cardinal above it, we force a set model ā¦