There is a need to develop a suitable computational grammar formalism for free word order languages for two reasons: First, a suitably designed formalism is likely to be more efficient. Second, such a formalism is also likely to be linguistically more elegant and satisfying. In this paper, we describe such a formalism, called the Paninian framework, that has been successfully applied to Indian languages. This paper shows that the Paninian framework applied to modern Indian languages gives an elegant account of the relation between surface form (vibhakti) and semantic (karaka) roles. The mapping is elegant and compact. The same basic account also explains active-passives and complex sentences. This suggests that the solution is not just adhoc but has a deeper underlying unity. A constraint based parser is described for the framework. The constraints problem reduces to bipartite graph matching problem because of the nature of constraints. Efficient solutions are known for these problems. It is interesting to observe that such a parser (designed for free word order languages) compares well in asymptotic time complexity with the parser for context free grammars (CFGs) which are basically designed for positional languages.

The paper describes the overall design of a new two stage constraint based hybrid approach to dependency parsing. We define the two stages and show how different grammatical construct are parsed at appropriate stages. This division leads to selective identification and resolution of specific dependency relations at the two stages. Furthermore, we show how the use of hard constraints and soft constraints helps us build an efficient and robust hybrid parser. Finally, we evaluate the implemented parser on Hindi and compare the results with that of two data driven dependency parsers.

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The Paninian* framework proposes karakas as semanticosyntactic relations that play a crucial role in mediating between surface form and meaning. The framework accounts for theta-role assignment, active passive, and control in a uniform manner. It has been successfully used in building an extremely fast prototype machine-translation system between two Indian languages. The constraint parser and the generator are designed with information theoretic considerations. Paninian framework is particularly suited to free word order languages. As most human languages are relatively word-order free, the Paninian framework should be explored as a serious contender for sucll languages. Based on the Paninian theory, the concept of language accessor or anusaraka has emerged, which has the potential to overcome the language barrier in India.

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