$ EXAMPLE GRAMMAR FROM PAGE 264 OF COMPILER DESIGN THEORY
<S> -> <A> <B>;
<S> -> 'b' <C>;
<A> -> ;
<A> -> 'b';
<B> -> ;
<B> -> 'a' <D>;
<C> -> <A> <D>;
<C> -> 'b';
<D> -> 'a' <S>;
<D> -> 'c';