The problem of generating a cost-minimal edit script between two trees has many important
applications. However, finding such a cost-minimal script is computationally hard, thus the
only methods that scale are approximate ones. Various approximate solutions have been
proposed recently. However, most of them still show quadratic or worse runtime complexity
in the tree size and thus do not scale well either. The only solutions with log-linear runtime
complexity use simple matching algorithms that only find corresponding subtrees as long as …

► Exact approaches do not scale at all► Most existing contributions approximate the
minimal edit script▶ Finding a good approximation is still hard► Elaborated solutions: O
(n2) or worse runtime complexity► Simple solutions: O (n log n) complexity but not robust⇒
No robust and scalable solutions exist