Automatic Grammar Induction for Grammar Based Genetic Programming

This paper discusses selected aspects of evolutionary search algorithms guided by grammars, such as Grammar Guided Genetic Programming or Grammatical Evolution. The aim of the paper is to demonstrate that, when the efficiency of the search process in such environment is considered, it is not only the language defined by a grammar that is important, but also the form of the grammar plays a key role. In the most common current approach, the person who sets up the search environment provides the grammar as well. However, as demonstrated in the paper, this may lead to a sub-optimal efficiency of the search process. Because an infinite number of grammars of different forms can exist for a given language, manual construction of the grammar which makes the search process most effective is generally not possible. It seems that a desirable solution would be to have the optimal grammar generated automatically for the provided constrains. This paper presents possible solutions allowing for automatic grammar induction, which makes the search process more effective.