By definition it is a CSL because of the case [email protected]
>bdb|bd (@ being alpha)
BUT if try to analyse the grammer, the production [email protected]
will never be used,
Since all productions have terminal symbols only except
Which will produce @@@@@....S on recursion but never ever [email protected]
will be seen in any permutation of the grammer.
Also, the rest of the gammer is right recursive therefore I think it should be Regular.
Although in the book it is given as you explained, but still I have this doubt.
It will be very helpful of you to kindly clear it.