[PDF] Top 20 Parsing Linear Context Free Rewriting Systems with Fast Matrix Multiplication

... We refer to an LCFRS rule A → B C as single-initial if the leftmost endpoint of C is internal to a span of A, and dual-initial if the leftmost endpoint of C is the beginning of a span of A. Our algorithm will require the ... See full document

... Synchronous Context-Free Gram- mar (SCFG) (Uno and Yagiura, 2000; Zhang et ...the context of dependency parsing, where the need for formalisms with higher fan-out has been observed even in ... See full document

... the parsing complexity that comes with allowing discontinuities, this is a promising finding since it has already been shown for monolingual parsing that restricting the fan-out to 2 drastically reduces ... See full document

... eral LCFRS rules as input. G´omez-Rodr´ıguez et al. (2009) present an algorithm for binarization of LCFRSs while keeping fan-out as small as possi- ble. The algorithm is exponential in the resulting fan-out, and ... See full document

... only on sentences with a length of up to 15 words. On those sentences, we obtain 83.97. The crucial difference between DPSG rules and LCFRS rules is that the former explicitly specify the material that can occur in gaps ... See full document

... data-driven parsing with Linear Context-Free Rewriting System (LCFRS), markovized gram- mars are obtained through the annotation of bi- narization non-terminals during grammar bina- ... See full document

... LR parsing is a popular parsing strategy for variants of Context-Free Grammar ...mildly context-sensitive formalisms, such as Tree-Adjoining Gram- ...style parsing algorithm for ... See full document

... the context of natural language parsing, it has been observed that the vast majority of rules in real world applications can be factorized to some small length, and that excluding the worst-case rules which ... See full document

... the parsing problem for LCFRSs with f = 2 is NP-complete (Satta, 1992), and in known parsing algorithms the running time is exponentially affected by the rank r of the ...language parsing ... See full document

... PMCFG parsing algorithms (Kato et ...and linear, which means that they only support linear context-free rewriting sys- tems ... See full document

... While our results are mostly intractability re- sults, we see them as a first step towards a more finely grained understanding of the complexity of LCFRS parsing. Ruling out simple parameteri- zation by fan-out or ... See full document

... In practical natural language processing applic- ations the fan-out of the grammar is typically bounded by some small number. As an example, in the case of discontinuous parsing discussed above, we have f = 2 for ... See full document

... that parsing complexity also provides such an infinite ...the parsing complexity amounts to specifying a normalized binarization for grammars of arbitrary rank and fan-out, and compar- ing the resulting ... See full document

... guide parsing of an LCFRS ...ter parsing with the coarse grammar, the result- ing chart is pruned by removing all items that fail to meet a certain ...When parsing with the fine grammar, whenever a ... See full document

... However, this reduction converts a parser running in time OIwl 1"5 to a BMM checking algorithm running in time Om 3 the running time of the standard multiplication method, whereas our re[r] ... See full document

... to Linear Context-Free Rewriting Systems (LCFRS), but retains much of the notational and in- tuitive simplicity of Context-Free Grammar ... See full document

... Before parsing, we binarize the extracted LCFRS. For this we first apply Collins-style head rules, based on the rules the Stanford parser (Klein and Manning, 2003b) uses for NeGra, to mark the resp. head daughters ... See full document

... coupled context-free grammars (CCFG), introduced by Hotz and Pitsch ...a parsing algorithm for ...the parsing algorithm that is derived runs in time O(4 ϕ · |G| · |w| 2ϕ+2 ... See full document

... that Context-Free Grammar (CFG) does not provide enough expressivity to de- scribe natural ...CFG parsing, some of the information present in constituency treebanks, namely the annotation of ... See full document

... Abstract Recent results have established that there is a family of languages that is exactly the class of languages generated by three independently developed grammar formalisms: Tree Ad[r] ... See full document