We define a mesh current as the current that circulates around a mesh. If an element is located on a single mesh, such as vg1 or R2 in Fig. 4.16, it carries an element current just equal to this mesh current. If an element is located on the boundary between two meshes, such as R2 in the same figure, its element current is the algebraic sum of the two mesh currents circulating through it. Labeling element currents with capital letters and mesh currents with lowercase letters, bout R1 and vg1 have the same element current il where