Gerhard Gentzen has been described as logic's lost genius whom Gödel called a better logician
than himself. This work comprises articles by leading proof theorists attesting to Gentzen's
enduring legacy to mathematical logic and beyond. The contributions range from philosophical
reflections and re-evaluations of Gentzen's original consistency proofs to the most recent
developments in proof theory. Gentzen founded modern proof theory. His sequent calculus and
natural deduction system beautifully explain the deep symmetries of logic. They underlie modern
developments in computer science such as automated theorem proving and type theory.
