In mathematics, the Redmond–Sun conjecture, raised by Stephen Redmond and Zhi-Wei Sun in 2006, states that every interval [x m, y n] with x, y, m, n ∈ {2, 3, 4, ...} and x m ≠ y n contains primes with only finitely many exceptions. Namely, those exceptional intervals [x m, y n] are as follows: The conjecture has been verified for intervals [x m, y n] with endpoints below 4.5 x 1018. It includes Catalan's conjecture and Legendre's conjecture as special cases. Also, it is related to the abc conjecture as suggested by Carl Pomerance.