ABSTRACT
Degenerate elliptic differential equations have been studied by many authors: Edmunds and Peletier, Kruskov, Murty and Stampacchia, Trudinger... (see [4], [8], [9], [12] and [13]) more recently by Fabes, Jerison, Kenig and Serapioni (see [5], [6]) and in the larger context of the Dirichlet forms of diffusion type by Biroli and Mosco ([2], [3]).
