حل تمرین نظریه محاسبات/فصل دوم/حل تمرین ۲-۱۹

S -> aSb | bY | Ya
Y -> bY | aY | ɛ

The CFG is showing something like : {a}ⁱ{a,b}*{b}^j where i=j
This results the language of any permutation of 'a's and 'b's. {a,b}*

So the complement of this CFG would be an empty language.