Fernando Pereira. Extraposition grammars. American Journal of Computational Linguistics, 9(4):243--255, 1981.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....the interpreter will try to join the graphs by matching directly the corresponding heads. As one can see, the only operations the interpreter needs from CGT are the canonical formation rules. The sentences are parsed with a wide coverage Portuguese syntax description [4] using the XG formalism [7]. In its actual state, the semantic interpreter only covers a tiny subset of that description. On the other hand, it performs some deduction on the database constructed from the input sentences. The interpreter accepts three types of sentences (see the appendix for examples) Declarative ....

Fernando C. N. Pereira. Extraposition grammars. American Journal of Computational Linguistics, 7(4):243--255, 1981.

....and therefore rule application may involve unification. They can be considered a notational variant of logic programs, in which goal satisfaction is viewed as acceptance of a string by a grammar, and where string manipulation concerns are hidden from the user. Extraposition Grammars (XGs) [24] allow the interspersing of skips on the left hand side, and these are routinely rewritten in their sequential order at the rightmost end of the rule, e.g. 2 : relmarker, skip(X) trace relpronoun, skip(X) In an XG rule, symbols on the left hand side following skips represent ....

F. Pereira. Extraposition grammars. American Journal for Computational Linguistics, 7:243--256, 1981.

....[Cho82] into the FA specifications for verbs and use it as a constituent for mediating unbounded dependencies. A detailed comparison of the chaining approach to unbounded dependencies (which is used in GB Theory, GPSG and TUG) with the direct approach (adopted by TAG, extraposition grammars [Per81] and discontinuous grammars [Dah89] is beyond the scope of this paper. 4.2 Unification Categorial Grammar Although TUG has been strongly influenced by work on categorial grammar, specifically unification categorial grammar (UCG) CKZ88] there is a marked difference in the ease in which ....

F.C.N. Pereira. Extraposition grammars. American Journal for Computational Linguistics, 7:243--256, 1981.

....paper described above) has its roots in logic grammars , the study of using logic programming techniques for computational linguistics. The logic grammar framework it studies is Dahl s Static Discontinuity Grammars (SDGs) which grew out of Definite Clause Grammars [22] and Extraposition Grammars [21] in a desire to handle discontinuous constituents and movement at a more fundamental level. However, little will be said about computation here, other than to note that grammars can be encoded naturally in SDGs, and that SDGs can be computed with an acceptable degree of efficiency [5, 6] This ....

....bought trace rel pronoun patricia bought that FIGURE 2.1. The extraposition grammar parse graph of a noun phrase. having moved, through relativization, the the left of Patricia bought the piano , and having then been replaced by the relative pronoun that 1 . Extraposition grammars, or XGs [21], allow a left hand side rule to refer to substrings to be skipped. These are repositioned in sequential order at the end of the rule s right hand side. For instance, the rules h relative clause rel marker; s i h np trace i h rel marker; skip(X) trace rel pronoun; skip(X) i allow us, ....

Fernando Pereira. Extraposition grammars. American Journal for Computational Linguistics, 7:243--256, 1981. 42

....this tradition by adapting to logic programming with continuations some of the techniques that were developed in logic grammars for computational linguistic applications. In particular, logic grammars have been augmented by allowing extra symbols and meta symbols in the left hand sides of rules [6, 17, 9]. Such extensions allow for straightforward expressions of contextual information, in terms of which many interesting linguistic phenomena have been described. We show that such techniques can be efficiently transfered to continuation passing binary programs, that their addition motivates an ....

.... [ Jill ] verb [photographed] verb [smiles] What is noteworthy about this example is that it shows how to use plain Prolog plus binarization to achieve the same expressive power which used to require more sophisticated grammar formalisms, such as Extraposition or Discontinuous Grammars [17, 9]. 6.3 Computation viewed as parsing Continuation Grammars are useful not only for linguistic or intrinsically grammatical examples, but can also serve to simplify the description of many problems which can be formulated in terms of a grammar. Example 14 For instance, we can sort a list of ....

F. Pereira. Extraposition grammars. American Journal for Computational Linguistics, 7:243--256, 1981.

....and therefore rule application may involve unification. They can be considered a notational variant of logic programs, in which goal satisfaction is viewed as acceptance of a string by a grammar, and where string manipulation concerns are hidden from the user. Extraposition Grammars (XGs) [Per81] allow the interspersing of skips on the left hand side, and these are routinely rewritten in their sequential order at the rightmost end of the rule, e.g. 1 : relmarker, skip(X) trace relpronoun, skip(X) In an XG rule, symbols on the left hand side following skips represent ....

F. Pereira. Extraposition grammars. American Journal for Computational Linguistics, 7:243-- 256, 1981.

....and therefore rule application may involve unification. They can be considered a notational variant of logic programs, in which goal satisfaction is viewed as acceptance of a string by a grammar, and where string manipulation concerns are hidden from the user. Extraposition Grammars (XGs) [20] allow the interspersing of skips on the left hand side, and these are routinely rewritten in their sequential order at the rightmost end of the rule, e.g. 1 : relmarker, skip(X) trace relpronoun, skip(X) In an XG rule, symbols on the left hand side following skips represent ....

F. Pereira. Extraposition grammars. American Journal for Computational Linguistics, 7:243--256, 1981.

....natural language processing. Interested reader can refer to [56, 39, 55] for top down and bottom up parsing in logic programming. Handling of long dependency is another difficult task in parsing, but most interested works have been based on the logic programming. Interested reader should refer to [54, 10, 9, 64, 3]. Part II: Natural Language Generation 7 Introduction As mentioned in Part I, natural language analysis is the process in which the system extracts the semantic meaning of the input text. The system may also be required to infer the intentions of the speaker from the text. On the other hand, ....

F. C. N. Pereira. Extraposition Grammars. American Journal of Computational Linguistics, Vol. 7, No. 4, pp. 243--256, 1981.

....algebra vocabulary to bear on syntactic issues is to show that in a sense, it is implicit in a great deal of earlier work. We present a few case studies which make this point in some detail. First, we shall consider Pereira s Extraposition Grammars (XG s) These were introduced in Pereira [16] as a formalism which could describe left extraposition phenomena in a way which is computationally sound (since the rules of the grammar could be translated to Prolog programs, thereby reducing parsing to proof search) sufficiently powerful to describe the phenomena in question, and yet simple ....

F. Pereira. Extraposition grammars. American Journal of Computational Linguistics, vol. 7, no. 4:243-256, 1981.

....for the work described in this paper. One was the augmentation of the grammar coverage. Not only in the sense that the grammar should have more rules, but it is also worth it to study the adaptability of this method to more powerful logic grammar formalisms, namely extraposition grammars [32] or Bound Movement Grammars [26, 4] Regarding Bound Movement Grammars formalism [26] that has been designed as a generalization of the Extraposition Grammars formalism [32] in order to maintain declarativity and descriptive simplicity when dealing with different kinds of movements of sentence ....

.... worth it to study the adaptability of this method to more powerful logic grammar formalisms, namely extraposition grammars [32] or Bound Movement Grammars [26, 4] Regarding Bound Movement Grammars formalism [26] that has been designed as a generalization of the Extraposition Grammars formalism [32] in order to maintain declarativity and descriptive simplicity when dealing with different kinds of movements of sentence constituents (in interrogative sentences, in relative clauses, for topicalization, for clitics in Latin languages, etc) a wide coverage grammar (with more than 200 rules) for ....

Fernando Pereira. Extraposition grammars. American Journal of Computational Linguistics, 9(4):243--255, 1981.

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