When n types of univalent ligands are competing for the binding to m types
of protein sites, the determination of the system composition at equilibriu
m reduces to the solving of a non-linear system of n equations in C = [0; 1
](n). We present an iterative method to solve such a system. We show that t
he sequence presented here is always convergent, regardless of the initial
value in C. We also prove that the limit of this sequence is the unique sol
ution in C of the non-linear system of equations.