This is an alternative form of KVL. Notice that if we had traveled counterclockwise, the result would have been +v1,-v5, +v4,-v3, and-v2, which is the same as before except that the signs are reversed. Hence, Eqs.(1.7) and (1.8) remain the same.
When voltage sources are connected in series, KVL can be applied to obtain the total voltage. The combined voltage① is the algebraic sum of the voltages of the