The Power of Extended Top-Down Tree Transducers
نویسندگان
چکیده
Extended top-down tree transducers (transducteurs g en eralis es descendants [Arnold, Dauchet: Bi-transductions de forêts. ICALP'76. Edinburgh University Press. 1976]) received renewed interest in the eld of Natural Language Processing. Here those transducers are extensively and systematically studied. Their main properties are identi ed and their relation to classical top-down tree transducers is exactly characterized. The obtained properties completely explain the Hasse diagram of the induced classes of tree transformations. In addition, it is shown that most interesting classes of transformations computed by extended top-down tree transducers are not closed under composition.
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عنوان ژورنال:
- SIAM J. Comput.
دوره 39 شماره
صفحات -
تاریخ انتشار 2009