DCG Formalism and Its Applying Example

This paper introduces DCG (Definite Clause Grammar) formalism proposed by Pereira and Warren, describes the translation process from DCG to Prolog clause, and then analyses its advantage and disadvantage when being applied to natural language processing. Finally, we introduce a DCG described natural language interface for database, which can deal with Chinese imperative sentence access to database. This program has been compeleted in IBM-PC computer.