Context free grammarContext free grammar is a formal grammar which is used to generate all possible strings in a given formal language. Context free grammar G can be defined by four tuples as: Where, G describes the grammar T describes a finite set of terminal symbols. V describes a finite set of non-terminal symbols P describes a set of production rules S is the start symbol. In CFG, the start symbol is used to derive the string. You can derive the string by repeatedly replacing a non-terminal by the right hand side of the production, until all non-terminal have been replaced by terminal symbols. Example:
L= {wcwR | w € (a, b)*}
Production rules: Now check that abbcbba string can be derived from the given CFG. By applying the production S → aSa, S → bSb recursively and finally applying the production S → c, we get the string abbcbba.
Next TopicCapabilities of CFG
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