2 - State of the art: grammatical inference

Abstract

This chapter presents a comprehensive discussion on the state of the-art of grammatical inference (GI). The fundamental definitions of language and grammar are explained in a simplified manner for beginners and intermediate-level researchers. The first part of Chapter 2 is dedicated to basic grammar definitions. The discussion starts with the standard grammar presentation referred as Backus–Naur form. After that, standard grammar representation is discussed along with the Chomsky hierarchy. Various grammar representations such as unstructured grammar, context sensitive grammar, context-free grammar, and regular grammar are covered. Other forms of grammar such as matrix grammar, random context-free grammar, valence grammar, and bag context grammar are explained using the rewriting mechanism. Learning algorithms, with their strengths and weakness, are presented later in the chapter. Finally, a comparative classification of different learning algorithms is presented. The key concepts presented in this chapter are a detailed and comprehensive review of approaches that have been proposed for GI, with the strengths and weaknesses of each approach. The approaches are classified based on the various factors. The analysis of each approach is conducted and presented in tabulated form for quick review.