Consider the augmented grammar with \+, *, (, ), id\ as the set of terminals. aligned S' & S \\ S & S + R R \\ R & R * P P \\ P & (S) id aligned If I_0 is the set of two LR(0) items \[S' S.], [S S. + R]\, then goto(closure(I_0), +) contains exactly __________ items.

GATE CSE 2022 Q29: Number of LR(0) items in goto on +

Consider the augmented grammar with $\{+, *, (, ), id\}$ as the set of terminals.

$\begin{aligned} S' &\to S \\ S &\to S + R \mid R \\ R &\to R * P \mid P \\ P &\to (S) \mid id \end{aligned}$

If $I_0$ is the set of two $LR(0)$ items $\{[S' \to S.], [S \to S. + R]\}$ , then $goto(closure(I_0), +)$ contains exactly __________ items.

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Answer: 5 (official GATE 2022 final answer key)

Concept used: goto moves the dot over the symbol, then takes the closure of the resulting items.

First step: Only $[S \to S. + R]$ moves on $+$ , giving $[S \to S + .R]$ ; now add the closure items for $R$ and $P$ .

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Source: official GATE 2022 CS question paper and final answer key, organised by IIT Kharagpur. Question paper · Answer key