Focal boundary value problems for nonlinear difference equations. I (Q919204)

The author investigates the uniqueness of solutions of the nth-order nonlinear difference equation \(u(t+n)=f(t,u(t),...,u(t+n-1)\) where \((A)\quad f: [a,+\infty)\times {\mathbb{R}}^ n\to {\mathbb{R}}\) is continuous and the equation \(u_{n+1}=f(t,u_ 1,u_ 2,...,u_ n)\) can be solved for \(u_ 1\) as a continuous function of the variables \(t,u_ 2,...,u_{n+1}\).