New posts in Proof Theory

Proving the existence of a proof without actually giving a proof

Can we continue a proof by contradiction even if we get to a contradiction?

What is exactly the difference between a definition and an axiom?

Why can't you prove the law of the excluded middle in intuitionistic logic (for layman)?

What is the correct reading of $\bot$?

Do we know if there exist true mathematical statements that can not be proven?

Minimal difference between classical and intuitionistic sequent calculus

What does "prove by induction" mean?

Why can't reachability be expressed in first order logic?

Can every proof by contradiction also be shown without contradiction?