Top-Down Tree Edit-Distance of Regular Tree Languages
نویسندگان
چکیده
We study the edit-distance of regular tree languages. The edit-distance is a metric for measuring the similarity or dissimilarity between two objects, and a regular tree language is a set of trees accepted by a finite-state tree automaton or described by a regular tree grammar. Given two regular tree languages L and R, we define the editdistance d(L,R) between L and R to be the minimum edit-distance between a tree t1 ∈ L and t2 ∈ R, respectively. Based on tree automata for L and R, we present a polynomial algorithm that computes d(L,R). We also suggest how to use the edit-distance between two tree languages for identifying a special common string between two context-free grammars.
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