FIRST & FOLLOR

Question

S -> A B
A -> f S f
A -> b b B d
B -> Ɛ
B -> c

First(S) =
First(A) =
First(B) =

Follow(S) =
Follow(A) =
Follow(B) =

Answer 1

Answers :-

First(S) = {b, f}
First(A) = {b, f}
First(B) = {ɛ, c}

Follow(S) = {$, f}
Follow(A) = {$, c}
Follow(B) = {$, d}

Comments

Could you explain to me why Follow(S) = {$, f, d}? Based on what I understand (which is very little), it would be: Follow(S) = {$, f}, because "f" is to the right of "S".

---

Follow (S) will be [ Follow(B) UNION {f, $} ]

Answer 2

 

First(S) = {b, f}

First(A) = {b, f}

First(B) = {ɛ, c}

 

Follow(S) = {$, f}

Follow(A) = {$, c,f}

Follow(B) = {$, d,f}