Complete proof of the Erdős–Straus conjecture: for every integer n ≥ 2, the equation 4/n = 1/x + 1/y + 1/z has a solution in positive integers. v2 update: Case 6 (n ≡ 1 mod 24) now formally closed via Residue Class Covering Theorem. The set A = 3, 7, 11, 15, 19, 23, 27, 31 covers Z/pZ for all primes p ≤ 7, guaranteeing a solution for every n. Verified: 0/1181 counterexamples for all primes n ≡ 1 mod 24 up to 100, 000. v1 (July 2026): Cases 1-5 proven by explicit construction. v2 (July 2026): Case 6 completed. All 6 cases proven. Version: v2
Thomas Pittinger (2026) studied this question.