Chapter 5: Context - Free Grammar

... B k A 1 A 2 A m 27 S-Grammars and Contemporary Programming Languages Many features of Pascal-like programming languages can be expressed with s-grammars. 28 Ambiguity A context- free grammar G is said ... which w∈L(G) is derived. Chapter 5: Context- Free Grammar Quan Thanh Tho qttho@cse.hcmut.edu.vn 20 Example 5.8 S → SS | aSb | bSa | λ w = aabb 21 Exhaustive Search Parsing •...

Ngày tải lên: 13/05/2014, 10:21

... subderivations into a full parse. 2 Notation for context- free grammars The reader is assumed to be familiar with context- free grammars. Our notation fol- 1Other relevant parsers simultaneously consider ... • For bilexicalized context- free grammars, O(n 4) is possible. • The O(n 4) result also holds for head au- tomaton grammars. • For a very common special case of these...

Ngày tải lên: 20/02/2014, 19:20

... Lexicalized context- free grammar (LCFG) is an attractive compromise between the parsing ef- ficiency of context- free grammar (CFC) and the elegance and lexical sensitivity of lexicalized tree- adjoining ... Shanker, and Weir, 1991; Vijay-Shanker and Weir, 1993a) that generate only a small superset of context- free languages. One such formalism is lex- icalized tree-adjo...

Ngày tải lên: 08/03/2014, 07:20

... "Generalized Context- Free Grammars and Multiple Context- Free Grammars", Trans. IEICE, J71-D-I, 5:7 5 8-7 65. Kasami, T. et al. 1988b. "On the Membership Prob- lem for Head Language ... significant to clarify the gen- erative capacities of such grammars and devices. Parallel multiple context- free grammars (pm- cfg's) and multiple context- free gra...

Ngày tải lên: 08/03/2014, 07:20

... inves- tigate adding more flexibility to synchronous context- free grammars by adding glue rules and phrases. 1 Introduction Synchronous context- free grammar (SCFG) is widely used for machine translation. ... A hyper- graph containing a unary cycle cannot be topo- logically sorted. Many algorithms for parame- ter tuning and coarse-to-fine decoding, such as the inside-outside algorithm...

Ngày tải lên: 17/03/2014, 00:20

... Padova via Gradenigo, 6/A I-35131 Padova, Italy satta@dei.unipd.it Abstract We consider the problem of parsing non-recursive context- free grammars, i.e., context- free grammars that generate finite languages. ... undecidable (Harrison, 1978). Following the ter- minology adopted above, this means that parsing a context- free input grammar on the basis of a context- free parsing...

Ngày tải lên: 17/03/2014, 08:20

... algorithm for computing n-gram probabil- ities from stochastic context- free grammars, a procedure that can alleviate some of the standard problems associated with n-grams (estimation from sparse ... contained in an existing n-gram will tell anything about the n-grams containing the new item. Stochastic context- free grammars (SCFGs), on the other hand, are not as suscep- tible t...

Ngày tải lên: 17/03/2014, 09:20

... can be described by polynomial-size ID/LP grammars. The results have im- plications for the description of free word order languages. 2 Introduction Context free grammars in immediate dominance ... be called symmetric.) Ordinary context- free grammars, on the other hand, "seem to require that all permutations of right-hand sides of productions be ex- plicitly listed, in ord...

Ngày tải lên: 17/03/2014, 20:20

... Syllable Structure in Context- Free Grammar 3.1 Manually Constructed Context- Free Grammar for Myanmar Syllable Structure Context free (CF) grammar refers to the grammar rules of languages ... Myanmar syllable in context- free grammar and parse the syllables using predictive top-down parsing technique to determine whether a given syllable can be recognized by...

Ngày tải lên: 17/03/2014, 22:20

... the MOR- phological PArser MORPA is provided with a probabilistic context- free grammar (PCFG), i.e. it combines a "conventional" context- free morphological grammar to fil- ter ... specific context. The ultimate effect of these tests is that incorrect recog- nition of highly frequent and very small inflectional suffixes, such as -e, -t, -d, -s, -r, -n, -en or -...

Ngày tải lên: 18/03/2014, 02:20