UGC NET CSE | June 2013 | Part 2 | Question: 25

Question

Which is the correct statement(s) for Non Recursive predictive parser?

$S1 : First(\alpha) = \{ t \mid \alpha_{\Rightarrow}$ * $t \beta \text{ for some string } \beta \} _{\Rightarrow}$ * $t \beta$

$S2: Follow(X) = \{ a \mid S_{\Rightarrow}$ * $ \alpha X a \beta \text{ for some string } \alpha and \beta\} $

• A. Both statements S1 and S2 are incorrect
• B. S1 is incorrect S2 is correct
• C. S1 is correct S2 is incorrect
• D. Both statements S1 and S2 are correct

Answer 1

Ans B) statements S1 is incorrect and S2 are correct

$\alpha \rightarrow \ast t\beta$

First(∝) there can be some string before t

$S\rightarrow \ast \alpha Xa\beta$

Here follow(X) must be a