PageHeader : Funkcialaj Ekvacioj, 33 (1990) 551-562 Title : On the Rate of Convergence of Solutions for the Singular Title : Perturbations of Gradient Obstacle Problems AuthorInfo : By AuthorInfo : Katsuyuki ISHII and Naoki YAMADA AuthorInfo : (Kobe University, Japan) section : §1. Introduction section : §2. Preliminaries section : §3. Main result section : §4. Some extensions subsection : 4.1 HJB equation with gradient constraint. subsection : 4.2 General fully nonlinear operator case. section : References