Macro Tree Transducers, Attribute Grammars, and MSO Definable Tree Translations
Macro Tree Transducers, Attribute Grammars, and MSO Definable Tree Translations
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宏树转换器、属性语法和 MSO 可定义树转换
DOI:
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发表时间:
1999
影响因子:
1
通讯作者:
S. Maneth
中科院分区:
文献类型:
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作者:
J. Engelfriet;S. Maneth
A characterization is given of the class of tree translations definable in monadic second-order logic (MSO), in terms of macro tree transducers. The first main result is that the MSO definable tree translations are exactly those tree translations realized by macro tree transducers (MTTs) with regular look-ahead that are single use restricted. For this the single use restriction known from attribute grammars is generalized to MTTs. Since MTTs are closed under regular look-ahead, this implies that every MSO definable tree translation can be realized by an MTT. The second main result is that the class of MSO definable tree translations can also be obtained by restricting MTTs with regular look-ahead to be finite copying, i.e., to require that each input subtree is processed only a bounded number of times. The single use restriction is a rather strong, static restriction on the rules of an MTT, whereas the finite copying restriction is a more liberal, dynamic restriction on the derivations of an MTT.