PageHeader : Funkcialaj Ekvacioj, 32 (1989) 301-321 Title : Characterization of a Class of Evolution Operators Generated Title : by Time-dependent Subdifferentials AuthorInfo : By AuthorInfo : Masahiro KUBO AuthorInfo : (University of Tokyo, Japan) section : 0. Introduction section : 1. Theorems section : 2. Proof of Theorem 1 section : 3. Proof of Theorem 2 subsection : 3.1. Lemmas subsection : 3.2. Estimates of approximate solutions subsection : 3.3. Convergence of approximate solutions section : 4. Proof of Theorem 3 section : 5. Some sufficient conditions section : References