Let $S$ be a proper fragment of $\mathit{ZFC}$, and let $S$ properly extend $\mathit{ZFC}^-$, i.e. $\mathit{ZFC}$ minus the power set axiom. Is there a countable ordinal $\alpha$ so that $L_\alpha$ is a model of $S$ if $S$ has a countable well founded model?
Countable $L_\alpha$ model for $S$ if $S$ has a countable well founded model?
Frode Alfson Bjørdal
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