Gerhard Gentzen

Gerhard Gentzen was a German mathematician and logician known for his foundational work in proof theory and intuitionistic logic. He introduced natural deduction, a systematic way to prove statements using rules that resemble natural reasoning. Gentzen's work distinguished between classical logic, which accepts the law of excluded middle (a statement is either true or false), and intuitionistic logic, which requires a constructive proof of existence. His techniques, including cut-elimination, influenced modern logic and computer science, providing tools to understand the nature of mathematical proofs and computations.