| 41. |
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| 42. |
- Ljunglöf, Peter, 1971
(författare)
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Expressivity and Complexity of the Grammatical Framework
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates the expressive power and parsing complexity of the Grammatical Framework (GF), a formalism originally designed for displaying formal propositions and proofs in natural language. This is done by relating GF with two more well-known grammar formalisms; Generalized Context-Free Grammar (GCFG), best seen as a framework for describing various grammar formalisms; and Parallel Multiple Context-Free Grammar (PMCFG), an instance of GCFG. Since GF is a fairly new theory, some questions about expressivity and parsing complexity have until now not been answered; and these questions are the main focus of this thesis. The main result is that the important subclass context-free GF is equivalent to PMCFG, which has polynomial parsing complexity, and whose expressive power is fairly well known. Furthermore, we give a number of tabular parsing algorithms for PMCFG with polynomial complexity, by extending existing algorithms for context-free grammars. We suggest three possible extensions of GF/PMCFG, and discuss how the expressive power and parsing complexity are influenced. Finally, we discuss the parsing problem for unrestricted GF grammars, which is undecidable in general. We nevertheless describe a procedure for parsing grammars containing higher-order functions and dependent types.
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| 43. |
- Ljunglöf, Peter, 1971
(författare)
-
Formalizing the dialogue move engine
- 2000
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Ingår i: Götalog Workshop on Semantics and Pragmatics of Dialogue.
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Konferensbidrag (refereegranskat)abstract
- In this paper we present a calculus for reasoning mathematically about rule-based dialogue systems – so called dialogue move engines developed in the TRINDI project. The calculus is similar to term rewriting systems and dynamic logic. It is defined using monads, which are used for describing programming languages, and in functional programming to capture computations with side-effects.
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| 44. |
- Ljunglöf, Peter, 1971
(författare)
-
Functional chart parsing of context-free grammars
- 2004
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Ingår i: Journal of Functional Programming. ; 14:6, s. 669-680
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Tidskriftsartikel (refereegranskat)abstract
- This paper implements a simple and elegant version of bottom-up Kilbury chart parsing (Kilbury, 1985; Wir´en, 1992). This is one of the many chart parsing variants, which are all based on the data structure of charts. The chart parsing process uses inference rules to add new edges to the chart, and parsing is complete when no further edges can be added. One novel aspect of this implementation is that it doesn’t have to rely on a global state for the implementation of the chart. This makes the code clean, elegant and declarative, while still having the same space and time complexity as the standard imperative implementations.
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| 45. |
- Ljunglöf, Peter, 1971
(författare)
-
Functional Programming and NLP
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Most of today's NLP software is developed using either a logic programming language such as Prolog, or a low-level imperative language such as C or C++. In this paper I will try to argue why the paradigm of functional programming (as opposed to logic and imperative programming) matters for natural language processing.
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| 46. |
- Ljunglöf, Peter, 1971
(författare)
-
Grammatical Framework and multiple context-free grammars
- 2004
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Ingår i: FG-04, 9th Conference on Formal Grammar.
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Konferensbidrag (refereegranskat)abstract
- We show that there is a simple one-to-one correspondence between Grammatical Framework with context-free backbone and Multiple Context-Free Grammars (MCFG). Since the parsing complexity for MCFGs is known to be polynomial in the length of the input, we get the same result for context-free GF.
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| 47. |
- Ljunglöf, Peter, 1971
(författare)
-
GRASP: Grammar-based Language Learning
- 2010
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Ingår i: SLTC-2010, 3rd Swedish Language Technology Conference.
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Konferensbidrag (refereegranskat)abstract
- We are developing a pedagogical tool to support language learning and training for children with communicative disabilities. The system has a graphical interface, where the user can move, replace, add, and in other ways modify, words or phrases. The system keeps the sentence grammatical, by automatically rearranging the words and changing inflection, if necessary. In this way we hope that the system stimulates the child to explore the possibilities of language.
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| 48. |
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| 49. |
- Ljunglöf, Peter, 1971
(författare)
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How to edit syntax trees on the surface
- 2011
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Ingår i: Presentation at the LOCI Workshop II: Type Dependency, Type Theory with Records, and Natural-Language Flexibility, 16-17 June 2011, London.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 50. |
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