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Link Grammar ( by Davy Temperley, Daniel Sleator & John Lafferty )

Link Grammar ( by Davy Temperley, Daniel Sleator & John Lafferty ). Syed Toufeeq Ahmed ASU. An example. Sentence: “ The cat chased a snake ” Link Grammar Representation:. Link Grammar (LG).

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Link Grammar ( by Davy Temperley, Daniel Sleator & John Lafferty )

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  1. Link Grammar( byDavy Temperley, Daniel Sleator & John Lafferty ) Syed Toufeeq Ahmed ASU

  2. An example Sentence: “The cat chased a snake” Link Grammar Representation:

  3. Link Grammar (LG) • Sequence of words is in the languageof link grammar if there is a way to drawlinks between words in such a way that • Planarity : The linksdo not cross. • Connectivity : The linksconnect to all the words of the sequence together. • Satisfaction: The links satisfy the linking requirement of each word in the sentence. • Exclusion: No two links may connect the same pair of words.

  4. Dictionary and the linking requirement of words in it

  5. Dictionary encoding

  6. Previous example Sentence: “The cat chased a snake” Link Grammar Representation:

  7. Violation of rule 1 (planarity) • “ The Mary chased cat ”

  8. Difficult situations • Coordinating conjunctions such as ‘and ’ in “The dog chased and bit Mary”, here links would cross. • Non-referential use of ‘it ’. “It is likely that John will go” is correct. “The cat is likely that John will go” is incorrect. The Parser fails here, there is a Post-Processor to handle these situations.

  9. Biomedical Example -- 1 • "GABA mediates the inhibitory effect of NO on the AVP and OXT responses to insulin-induced hypoglycemia."

  10. 1 2 Linkage

  11. Bio-text example 2 • “We demonstrate that INSULIN treatment results in activation of both PLD1 and PLD2 in appropriate cell types when the appropriate upstream intermediate signalling components, i.e. PKCalpha and PLCgamma, are expressed at sufficient levels."

  12. References • Daniel Sleator and Davy Temperley. 1991. Parsing English with a Link Grammar. Carnegie Mellon University Computer Science technical report , 1991. • Daniel Sleator and Davy Temperley. 1993. Parsing English with a Link Grammar. Third International Workshop on Parsing Technologies • John Lafferty, Daniel Sleator, and Davy Temperley. 1992. Grammatical Trigrams: A Probabilistic Model of Link Grammar. Proceedings of the AAAI Conference on Probabilistic Approaches to Natural Language, October, 1992 • Dennis Grinberg, John Lafferty and Daniel Sleator. 1995. A robust parsing algorithm for link grammars Proceedings of the Fourth International Workshop on Parsing Technologies, Prague, September, 1995

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