New posts in Peano Axioms

Understanding nonstandard Peano arithmetic

A basic question about $\Rightarrow$

Can proper elementarily equivalent end extensions ever be definable?

How does Peano Postulates construct Natural numbers only?

Peano's successor function

Are there "interesting" theorems in Peano arithmetic, that only use the addition operation?

How to prove that first-order PA proves the consistency of each of its finite sub-theories?

Does the successor function imply order?

Do we have to prove how parentheses work in the Peano axioms?

Is it true that $0\in 1$?