On the consistency of ZF with an elementary embedding from Vλ+2 into Vλ+2
On the consistency of ZF with an elementary embedding from Vλ+2 into Vλ+2
According to a theorem due to Kenneth Kunen, under ZFC, there is no ordinal [Formula: see text] and nontrivial elementary embedding [Formula: see text]. His proof relied on the Axiom of Choice (AC), and no proof from ZF alone is has been discovered. [Formula: see text] is the assertion, introduced …