3.3.3 Discrete divergence theorem: Why is the flow across the “cut" in the figure equal to the sum of the flows from the individual nodes A,B,C,D? Note: This is true

even if flows liked, d1- d6 from nodes like A are nonzero. If the current law holds and each node has zero net flow,then the exercise says that the flow across every cut is zero.

Fig: 1