GATE CS 2019 Set 1 — Question 29
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.NAT+1 / -0MediumFirst & Follow SetsSyntax AnalysisCompiler Design
Compiler Design → Syntax Analysis → First & Follow Sets
Last updated
Question
Consider the grammar given below:
Let a, b, d, and $ be indexed as follows:
Compute the FOLLOW set of the non-terminal B and write the index values for the symbols in the FOLLOW set in the descending order. (For example, if the FOLLOW set is {a, b, d, $}, then the answer should be 3210)Answer: _______
A → BDLet a, b, d, and $ be indexed as follows:
| a | b | d | $ |
|---|---|---|---|
| 3 | 2 | 1 | 0 |
Correct answer
31 to 31
Solution
Given grammar:
We need to find .
So, .
The indices in descending order are 3, 1.
Concatenating them gives 31.
A → BDWe need to find .
1.Look for productions where appears on the RHS:
A → BD.2. includes .
.So, .
3.Since , also includes .
4.Look for productions where appears on the RHS: .
5. includes .
So, .Thus, .Using the given indices:The indices in descending order are 3, 1.
Concatenating them gives 31.
Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE CS question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on Syntax Analysis
2026 Set 2 Q17In C runtime environment, which one of the following is stored in heap?2026 Set 2 Q19Consider the following three ANSI-C programs, P1, P2, and P3. P1 [code] P2 [code] **P3**…2026 Set 1 Q27Consider the following C statements: Which of the following options is/are correct? [figure]2026 Set 1 Q28Which of the following statements is/are true?2026 Set 2 Q35A lexical analyzer uses the following token definitions - - …