Before revision:  We extend this approach to a system consisting of R receptors and L ligands to derive the probability density function p(r;R,L) , to find r bound receptor-ligand complexes at thermal equilibrium.
After revision:  We extend this approach to a system consisting of R receptors and L ligands to derive the probability density function p(r;R,L) to find r bound receptor-ligand complexes at thermal equilibrium.