PageHeader : Funkcialaj Ekvacioj, 38 (1995) 81-99 Title : Abstract Second Order Differential Equations with Title : Applications AuthorInfo : By AuthorInfo : Angelo FAVINI and Atsushi YAGI AuthorInfo : (University of Bologna, Italy and Himeji Institute of Technology, Japan) AuthorInfo : Dedicated to Professor Hiroki Tanabe on the occasion of his 60th birthday section : 0. Introduction section : 1. Preliminaries section : 2. The equation (E) in the case $D(B)\subseteq D(A)$ section : 3. The case $D(A)$ strictly contained into $D(B)$ section : References