NIELIT 2022 April Scientist B | Section B | Question: 64

Question

Which of the following statements about the parser is/are correct?

1. Canonical $\text{LR}$ is more powerful than $\text{SLR}.$
2. $\text{SLR}$ is more powerful than $\text{LALR}.$
3. $\text{SLR}$ is more powerful than canonical $\text{LR}.$

 

• A. $\text{(I)}$ only
• B. $\text{(II)}$ only
• C. $\text{(III)}$ only
• D. $\text{(II)}$ and $\text{(III)}$ only

Answer 1

 

$CLR$ and $LR(1)$ parser is same.

1. As we can see since $SLR \subseteq LR(1)$. Therefore this option is correct.
    
2. $SLR \subseteq LALR(1)$ therefore $LALR(1)$ is more powerful than $SLR$.
    
3. $SLR \subseteq CLR$ or $LR(1)$, therefore $CLR$ is more powerful.
   
   Answer: A