Existence and uniqueness of positive solutions of a system of nonlinear algebraic equations

Nonlinear or linear algebraic systems appear as steady-state equations in continuous and discrete dynamical models (e.g., reaction-diffusion equations [14,19], neural networks [5,6,15,22] compartmental systems [2,4,11,12,16,17], population models [13,21]). Next we mention some typical models. Compartmental systems are used to model many processes in pharmacokinetics, metabolism, epidemiology and ecology. We refer to [16,17] as surveys of basic theory and applications of linear and nonlinear compartmental system without and with delays. A standard form of a linear compartmental system with delays is