... 2008.5 J. Liang, R. Nagel, and T J. Xiao, “Approximation theorems for the propagators of higher orderabstract Cauchy problems,” Transactions of the American Mathematical Society, vol. 360, no. 4, ... solution of 1.1 in a Banachspace X: A generates a compact semigroup S· of uniformly bounded linear operators on a Banach space X. The function a · is real valued and locally integrable on 0, ... N’Gu´er´ekata, A Cauchy problem for some fractional abstract di fferential equation with nonlocal conditions,” Nonlinear Analysis: Theory, Methods & Applications, vol. 70, no. 5, pp. 1873–1876,...