A Note on Recursive Models of Set Theories
Antonella Mancini, Domenico Zambella · Notre Dame Journal of Formal Logic · 2001
We construct two recursive models of fragments of set theory. We also show that the fragments of Kripke-Platek set theory that prove $ \varepsilon$-induction for $ \Sigma_1$-formulas have no recursive models but the standard model of the hereditarily finite sets.