Metavariable

Abstract: An efficient LFG parser implementation of Indian languages in general and Bangla in particular has been discussed. It has been shown that the classical technique of nonconfigurational syntactic encoding principles lead to too many disjunctive constraints to be satisfied by the parser. Noting that most of the disjunctions do not exist if an a priori knowledge of the verb is available, a "delayed" syntactic encoding formalism has been proposed. The points of syntactic encoding of noun phrases have been treated a "forward references" that are to be temporarily maintained in a "symbol table" for later precipitation. The proposed solution has two parts. The first part deals with identification of forward reference points, which is done by introducing a new metavariable and augmenting the scope of the Locate operator. The second part deals with precipitation of forward references through special schemata called m-structure schemata projected by the verb. An extension of the solution to one type of Bangla complex sentences has also been proposed (in the Appendix). Implementation notes based on object-oriented programming principles have been provided.

Abstract: The paper develops a mathematical theory in the spirit of categorical algebra that provides a model theory for second-order and dependently-sorted syntax. The theory embodies notions such as -equivalence, variable binding, capture-avoiding simultaneous substitution, term metavariable, meta-substitution, mono and multi sorting, and sort dependency. As a matter of illustration, a model is used to extract a second-order syntactic theory, which is thus guaranteed to be correct by construction.