Equivalences between Ranked and Unranked Weighted Tree Automata via Binarization
Toni Dietze · 2016
Encoding unranked trees to binary trees, henceforth called binarization, is an important method to deal with unranked trees.For each of three binarizations we show that weighted (ranked) tree automata together with the binarization are equivalent to weighted unranked tree automata; even in the probabilistic case.This allows to easily adapt training methods for weighted (ranked) tree automata to weighted unranked tree automata.