Show that \(I \times J\) is a bicluster with coherent values if and only if, for any \(i_{1}, i_{2} \in I\) and \(j_{1}, j_{2} \in J\), \(e_{i_{1} j_{1}}-e_{i_{2} j_{1}}=e_{i_{1} j_{2}}-e_{i_{2} j_{2}}\).