[PDF] Top 20 Efficient Parsing of Well Nested Linear Context Free Rewriting Systems

... 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

... 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

... Linear Context-Free Rewriting Systems (LCFRSs) (Vijay-Shankar et ...subsumes context- free grammars (CFGs) and tree adjoining grammars (TAGs), as well as the ... 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

... 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

... more efficient algorithm is presented in (Kuhl- mann and Satta, 2009), working in time O(|p|) in case of f = ...Other linear time algorithms for rank re- duction are found in the literature (Zhang et ... 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

... Recognition and parsing for a given LCFRS can be carried out in polynomial time on the length of the input string. This is usually done by exploit- ing standard dynamic programming techniques; see for instance ... See full document

... equivalence means that the derivations of the orig- inal grammar can be reconstructed using some sim- ple homomorphism (c.f. Nijholt, 1980). Our contri- bution is significant because the existing algorithms for ... 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

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

... Coarse-to-fine parsing (Charniak et al., 2006) is a technique to speed up parsing by exploiting the information that can be gained from parsing with simpler, coarser ...as well, which greatly ... See full document

... The intuition behind matrices of the type of T (meaning T and, as we see later, products of T with itself, or its transitive closure) is that each cell indexed by (i, j) in such a matrix consists of all nonterminals that ... 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

... A problem of the previous estimate is that with a large number of non-terminals the computation of the estimate requires too much space. Our ex- periments have shown that for treebank parsing where we have, after ... See full document

... a well-known fact 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 ... See full document

... of context-free pars- ing, without reducing ...all parsing archi- tectures, yet the methods mentioned above only con- sider spans of length two or ... 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

... The function derivable is the most time- consuming part of the recogniser, because it is the only part whose overall runtime grows cubically with sentence length. The inner loop of the function iterates over the possible ... See full document

... In Equation 5 we assume there are b unique clas- sifiers, one for each possible beam-width value be- tween 0 and b − 1, but this level of granularity is not required. Choosing the number of classification bins to ... See full document