[PDF] Top 20 Optimal Reduction of Rule Length in Linear Context Free Rewriting Systems

... 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 standard, ... See full document

... synchronous context-free grammar (SCFG) (Chiang, 2007; Zollmann and Venugopal, 2006; Hoang and Koehn, 2010), in par- ticular inversion transduction grammar (ITG) (Wu, ...synchronous rule (Wu, ... See full document

... We follow essentially the same approach as Nederhof and Satta (2011b), and reduce the prob- lem of computing the prefix probabilities for PLCFRSs to the well-known problem of comput- ing inside probabilities for PLCFRSs. ... See full document

... 1997) and Tiger (Brants et al., 2002) corpora, or those that can be extracted from traces such as in the Penn treebank (Marcus et al., 1993) annota- tion. However, the computational complexity is such that until now, the ... See full document

... has optimal time complexity, since it works in linear time with respect to the input production ...the reduction, can also be used for finding binarizations for LCFRS with fan-out larger than two, ... See full document

... Nakanishi et al. (1998) develop a matrix multiplication parsing algorithm for multiple context-free grammars (MCFGs). When these grammars are given in a binary form, they can be reduced to binary LCFRS. ... See full document

... The rule may in addi- tion generate (k + 1)k terminal place-holders (the k 2 nonterminal markers and string ends separating maximal terminal ...k rule appli- cations, without replacing terminal ... 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 of all ... 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 ... 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 synchronous ... See full document

... Under a theoretical perspective, 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 grammar. ... See full document

... each rule yields a tabular parsing algorithm with minimum ...an optimal trade-off between rank and fan-out” in order to minimize parsing complexity – in fact, no such trade-off is necessary, as rank 2 is ... See full document

... One possibility to obtain faster parsing is to reduce the fan-out of the grammar by reducing the number of gaps in the trees from which the grammar is ex- tracted. This has been done by Maier et al. (2012) who transform ... See full document

... Well-known Reactive Systems ➤ Term rewriting systems ➤ Graph rewriting systems ➤ via cospans ➤ Simple process calculi ➤ with terms up to structural congruence... ➤ a relative pushout RPO[r] ... See full document

... The algorithm is deceptively simple. Most of the work is in producing all items that can be deduced from a given item and items in the chart. This in- volves iterating over all grammar rules with matching labels, and ... See full document

... a context-free grammar) over the vocabulary of graph elements (labelled nodes and edges), where each word (in the sense of formal language theory) generated by the grammar represents one of the possible ... See full document

... In a tree, a node labeled with a terminal symbol is called a lexical node. A TAG is called lexicalized if each of its elementary trees has at least one lexical node. Observe that a lexicalized grammar cannot generate the ... See full document

... a context for such a process. Naturally, one hopes that the context will lead to success defined for such a computation, but it is generally not easy to make a right decision leading to ... See full document

... requested conditions, then it will be sent out of the membrane or it enters into the inner membrane if any exists. If both the conditions „in‟ and „out‟ are satisfied by choosing nondeterministically, the graph either ... See full document

... of rewriting in the regions and the type tin of the system Π, the first phase of the 2dRM G is simulated in region 1 starting from start symbol (array) S except that in the strings generated the last symbol will ... See full document