Since we are going to apply KCL, it seems that the simplest networks to consider are those whose only sources are independent current sources. This is not always true, as we shall see,but we shall begin with an example of this type.In network shown in Fig. 4.2(a), there are three nodes, dashed and numbered as shown. [This is easier to see in the redrawn version of Fig. 4.2(b).] Since there are four elements connected to node 3, we select it as the reference node, identifying it by the ground connection shown.