has a nontrivial solution in integers and primes greater than 3, then must be a double Wieferich pair, as proved in 2000 by
Mihailescu (Steiner 1998, Peterson 2000).
Peterson, I. "MathTrek: Zeroing In on Catalan's Conjecture." Dec. 4, 2000. http://www.sciencenews.org/20001202/mathtrek.asp.Steiner,
R. "Class Number Bounds and Catalan's Equation." Math. Comput.67,
1317-1322, 1998.