  We study existence, uniqueness, and distributional aspects of generalized
solutions to the Cauchy problem for first-order symmetric (or Hermitian)
hyperbolic systems of partial differential equations with Colombeau generalized
functions as coefficients and data. The proofs of solvability are based on
refined energy estimates on lens-shaped regions with spacelike boundaries. We
obtain several variants and also partial extensions of previous results and
provide aspects accompanying related recent work by C. Garetto and M.
Oberguggenberger.
