}\left( {{\pi }_{S}} \right)}\left| {{B}_{{{R}_{j}}}}\left( {{\pi }_{S}} \right) \right| \\   & =\tfrac{{{\left| {{B}_{{{R}_{j}}}}\left( {{\pi }_{S}} \right) \right|}^{0}}}{\left| {{B}_{{{R}_{j}}}}\left( {{\pi }_{S}} \right) \right|+\left( 