the choice of whether to use A or M to merge with C. If divergence(A, N) ??? divergence(A, M) is small, it makes sense to merge A and C to create a new set N that is almost as coherent as M. On the other hand, if the difference is large, we would prefer to replace A with its superset M as the merging candidate to C.In practice, we use d(A, C) to approximate divergence(A, N): we check whether ?? =