Degenerate triply nonlinear problems with nonhomogeneous boundary conditions

The paper addresses the existence and uniqueness of entropy solutions for the degenerate triply nonlinear problem: b(v)(t) - div a (v, del g(v)) = f on Q := (0, T) x Omega with the initial condition b(v(0, center dot)) = b(v(0)) on Omega and the nonhomogeneous boundary condition "v = u" on some part of the boundary (0, T) x partial derivative Omega". The function g is continuous locally Lipschitz continuous and has a flat region [A(1), A(2),] with A(1) <= 0 <= A(2) so that the problem is of parabolic-hyperbolic type.