Existentially closed structures and Gödel's second incompleteness theorem
Zofia Adamowicz, Teresa Bigorajska · Journal of Symbolic Logic · 2001
Abstract We prove that any 1-closed (see def 1.1) model of the Π2 consequences of PA satisfies ¬Cons PA which gives a proof of the second Gödel incompleteness theorem without the use of the Gödel diagonal lemma. We prove a few other theorems by the same method.