All Questions

The following question is whether $\sf PA$ is synonymous or even bi-interpretable with a theory about counting objects in finite sets. Counting Theory: $\textbf{Logic:}$ Bi-sorted first order logic ...

This question is very close to this old MSE question of mine, which is still unanswered. Is there an (ideally reasonably-natural!) expansion of the structure $(\mathbb{N};+)$ in a finite language ...

The following question is about patterns of synonymy relationships around two theories, $T^+$ and $\sf PA$. For purposes of self inclusiveness I'll re-iterate $T$ and its extensions. $\textbf{Logic:}$ ...