It's relevant to any kind of dependency graph. Essentially it's converting A A / \ / \ Cv2 B in

It's relevant to any kind of dependency graph. Essentially it's converting A A / \ / \ Cv2 B into | B \ \ \ Cv1 \ Cv1 \ / Cv2 Suppose some exported symbol, X, didn't change from Cv1 to Cv2. In the former, A gets two copies of X depending on which path it took up the dependency tree. In the latter, there's only one copy since both paths terminate in the same place.