[Solved]: Removing identical variables in CFG Unit Productions

Problem Detail: 

Productions of the form A-> A are removed immediately, but what if the production is of the form A -> AA?

example: A -> AA | a

Asked By : Sebastien

Answered By : Deepu

In you example the production A->AA can not be removed. If that production is removed then the language described by the grammar will change. But in case of a production like A->A, the removal will not affect the language described by the Grammar.

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Question Source : http://cs.stackexchange.com/questions/12746