igate booklet question

Question

Consider the following grammar: 

Prog → {S}  

S→ Prog X; | Y = z;  

X →ϵ |S Prog  

Y → SZ  

Z→id  

Determine follow(S) from the above grammar. 

(A) { } , id}  

(B) { }, ϵ , id} 

(C) { },{ id}  

(D ) { },{ id,ϵ }

Comments

(C) Follow(S) => { }, {, id }

Answer 1

 To find Follow(S), mark where is 'S' in given Productions : 

Prog → {S}  

S→ Prog X; | Y = Z;  

X →ϵ |S Prog  

Y → SZ  

Z→id 

 

Follow(S) = '}' $\cup$ First(Prog) $\cup$ First(Z) 

= '}' $\cup$ '{' $\cup$ 'id'

---

 

Follow(S) = { }, {, id }

Option C is Correct Answer.