Before revision:  This extension allows us to illustrate two aspects of this problem which we have not seen mentioned in existing literature , namely, a) a symmetry to be expected in the equilibrium distribution of the number of bound complexes under exchange of R and L and b) the number of bound complexes obtained from chemical kinetic equations has an exact correspondence to the maximum probable value of r from the expression for p(r;R,L).
After revision:  This extension allows us to illustrate two aspects of this problem which are not apparent in the single receptor problem , namely, a) a symmetry to be expected in the equilibrium distribution of the number of bound complexes under exchange of R and L and b) the number of bound complexes obtained from chemical kinetic equations has an exact correspondence to the maximum probable value of r from the expression for p(r;R,L).