The Logically Simplest Form of the Infinity Axiom

Franco Parlamento, Alberto Policriti
1988 Proceedings of the American Mathematical Society  
We provide a way of expressing the existence of infinite sets in the first order set theoretic language, which is of the lowest possible logical complexity.
doi:10.2307/2047565 fatcat:njpjp4zh75f55d3uf4ksqiuk3e