منابع مشابه
Synchronous Forest Substitution Grammars
The expressive power of synchronous forest (tree-sequence) substitution grammars (SFSG) is studied in relation to multi bottom-up tree transducers (MBOT). It is proved that SFSG have exactly the same expressive power as compositions of an inverse MBOT with an MBOT. This result is used to derive complexity results for SFSG and the fact that compositions of an MBOT with an inverse MBOT can comput...
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Synchronous tree substitution grammars are a translation model that is used in syntax-based machine translation. They are investigated in a formal setting and compared to a competitor that is at least as expressive. The competitor is the extended multi bottom-up tree transducer, which is the bottom-up analogue with one essential additional feature. This model has been investigated in theoretica...
متن کاملAn alternative to synchronous tree substitution grammars
Synchronous tree substitution grammars (stsg) are a (formal) tree transformation model that is used in the area of syntax-based machine translation. A competitor that is at least as expressive as stsg is proposed and compared to stsg. The competitor is the extended multi bottom-up tree transducer (mbot), which is the bottom-up analogue with the additional feature that states have non-unary rank...
متن کاملPreservation of Recognizability for Synchronous Tree Substitution Grammars
We consider synchronous tree substitution grammars (STSG). With the help of a characterization of the expressive power of STSG in terms of weighted tree bimorphisms, we show that both the forward and the backward application of an STSG preserve recognizability of weighted tree languages in all reasonable cases. As a consequence, both the domain and the range of an STSG without chain rules are r...
متن کاملAn Alternative to Synchronous Tree Substitution Grammars 3 2 Preliminaries
Synchronous tree substitution grammars (stsg) are a (formal) tree transformation model that is used in the area of syntax-based machine translation. A competitor that is at least as expressive as stsg is proposed and compared to stsg. The competitor is the extended multi bottom-up tree transducer (mbot), which is the bottom-up analogue with the additional feature that states have non-unary rank...
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ژورنال
عنوان ژورنال: Acta Cybernetica
سال: 2017
ISSN: 0324-721X
DOI: 10.14232/actacyb.23.1.2017.15