In Leveque's "Numerical Methods for Conservation Laws", Ch. 3.1.1., he says that given a system of Hyperbolic PDE's and a point $(\bar{t},\bar{x} )$, its domain of dependence $D(\bar{t},\bar{x} )$ is always a bounded set. The domains of dependence here is defined by the minimal size of an initial data set needed to determine the solution's value at a given point.
My question: Wikipedia defines hyperbolicity of a system by its eigenvalues. How can I proceed from this definition to prove the boundedness of the domain of dependence?
Thanks