Canonicability of the first order system of hyperbolic equations

The paper establishes a condition for the first order hyperbolic system (with a boundary condition at infinity) to have a solution that can be expressed by the second kind Volterra operator. On the basis of this condition, some canonical forms (for instance Dirac-type system) of the first order hyperbolic system can be sorted. The suitability of this condition in inverse scattering problem for the first order hyperbolic system on the half line is given as an application.