A formalism for the description of question answering systems

  • Camilla Schwind
Part of the Lecture Notes in Computer Science book series (LNCS, volume 63)


The following article presents a formalism for the description of a natural language based intelligent system. The meaning of natural language texts is to be represented by a state logic. This is an extension of predicate logic by special operators, which are applied to formulae and make their truth value dependent on the state of the world in which the formula is evaluated. The extension of the non-logical symbols depends also on the state of the world and it may change when a state changes. Natural language texts are described syntactically by a formal grammar, which is an extension of a CHOMSKY-grammar. The alphabet consists of complex symbols and the structure of these symbols is given by special rules. The derivation rules of our grammar are applied to symbols in different way which constitutes an extension of the usual method. The application of a rule is governed by the structure of the symbols and on applying one rule, we can derive a set of sentences. Natural language texts are translated into state logic formulae by special functions which are associated with the production rules. These functions depend on the syntactic structure of the sentences and on the world in which the sentences are evaluated. We will give a detailed example for the application of the whole formalism.


Noun Phrase Relative Clause Production Rule Predicate Symbol Structure Symbol 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1978

Authors and Affiliations

  • Camilla Schwind
    • 1
  1. 1.Technische Universität MünchenDeutschland

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