The equivalence of Fermat's Last Theorem and the non-existence of solutions
of a generalized nth order homogenous hyperbolic partial differential equa
tion in three dimensions and periodic boundary conditions defined in a cubi
c lattice is demonstrated for all positive integer, n > 2. For the case n =
2, choosing one variable as time, solutions are identified as either propa
gating or standing waves. Solutions are found to exist in the corresponding
problem in two dimensions.