Hi guys, I was told in the class, you can determine wether the CFG grammar is ambiguous by following the predict recursive decent parser's restriction. Please refer to the images.for example G1: the First(aA) = {a} First(a) = {a} First(aA) intersect First(a) != empty set, therefore G1 should be ambiguous, but this is wrong, can I get some explanation why using this restriction rule is not working on this problem, thanks Q13. Which of the following grammars are ambiguous?G1: S1 -> A B CA -> a AlaG2: S2 -> A B CA -> a A la-> b B | εB -> b B I bBс -> a CIEс -> a C 1 aG3: S1 -> A B CΑ -> α Α ΤεBb Bl bCa C I aG4: S2 -> A B CA -> a AI aBb Bl bC a Cla The requirement that a predictive parser be able to distinguish between choices in a grammar rulecan be stated in terms of First sets, as follows. Given the grammar rule:. | anA → α₁ | 0₂ |the First sets of any two choices must not have any tokens in common; that is,First(a.)First(α;) = Ø for all i ‡ j(Ø denotes the empty set)

Theory of computation which refers to the one it is a branch of Computer Science that is concerned…

Answered: Q13. Which of the following grammars…

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Related questions

Question

Hi guys, I was told in the class, you can determine wether the CFG grammar is ambiguous by following the predict recursive decent parser's restriction. Please refer to the images.

for example G1: the First(aA) = {a}

First(a) = {a}

First(aA) intersect First(a) != empty set, therefore G1 should be ambiguous, but this is wrong, can I get some explanation

why using this restriction rule is not working on this problem, thanks

Q13. Which of the following grammars are ambiguous?
G1: S1 -> A B C
A -> a Ala
G2: S2 -> A B C
A -> a A la
-> b B | ε
B -> b B I b
B
с -> a CIE
с -> a C 1 a
G3: S1 -> A B C
Α -> α Α Τε
Bb Bl b
Ca C I a
G4: S2 -> A B C
A -> a AI a
Bb Bl b
C a Cla

The requirement that a predictive parser be able to distinguish between choices in a grammar rule
can be stated in terms of First sets, as follows. Given the grammar rule:
. | an
A → α₁ | 0₂ |
the First sets of any two choices must not have any tokens in common; that is,
First(a.)
First(α;) = Ø for all i ‡ j
(Ø denotes the empty set)

Expert Solution

Step by step

Solved in 4 steps

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.

Similar questions