The Math Is Haunted

Lean, a programming language for formalizing mathematics, allows mathematicians to treat math as code, breaking it into structures, theorems, and proofs for sharing and verification. The article demonstrates Lean's functionality by proving simple theorems using tactics like rfl and exact. It illustrates how faulty axioms can lead to nonsensical proofs, emphasizing the importance of sound axioms. The piece concludes by mentioning efforts to formalize complex proofs like Fermat's Last Theorem in Lean, highlighting its potential for advancing mathematical knowledge.