Erratum: "Forcing and antifoundation"

Sato Kentaro pointed out a serious flaw in the proof of the main result (Truth Lemma 3.15) of [1]. Namely the greatest fixed point, Φ∞, of the operator Φ in definition 3.12 is taken to be inside the model M , while Φ∞ in lemma 3.6 is actually constructed outside M . The two definitions need not be identical (at least I can’t prove that they are). So what lemma 3.15 of [1] actually proves is that the Truth Lemma holds for models M such that the fixed point Φ∞ is the same when constructed inside and outside M .