  The propagation of analyticity for a solution u(t,x) to a nonlinear weakly
hyperbolic equation of order m, means that if u, and its time derivatives up to
the order m-1, are analytic in the space variables x at the initial time, then
they remain analytic for any time. Here we prove that such a property holds for
the solutions bounded in C-infinity of a special class of homogeneous equations
in one space variable, with time dependent coefficient.
