Question

Consider the production of the grammar S->AA A->aa A->bb Describe the language specified by the production grammar.

(a) L = {aaaa,aabb,bbaa,bbbb}

(b) L = {abab,abaa,aaab,baaa}

(c) L = {aaab,baba,bbaa,bbbb}

(d) L = {aaaa,abab,bbaa,aaab}

The question was asked in exam.

I would like to ask this question from Regular Expression in division Compiler Introduction of Compiler

Answer 1

Correct answer is (a) L = {aaaa,aabb,bbaa,bbbb}

The explanation: S->AA (substitute A->aa)

S->aaaa

S->AA (substitute A->aa )

S->aaA (substitute A->bb)

S->aabb

S->AA (substitute A->bb the A->aa)

S->bbaa

S->AA (substitute A->bb)

S->bbbb.