Recent questions tagged left-recursion / GATE Overflow for GATE CSE

0 votes

2 answers

1

COMPILER design
Is S->aS left recursive grammer?

Is S->aS left recursive grammer?

Mudit Jain

383 views

Mudit Jain asked Dec 27, 2022

0 votes

3 answers

2

Remove left recusrion and find out first and follow
Compute the FIRST and FOLLOW for the postfix grammar after removing the left recursion: $ S → S S+/ S S* /a$

Compute the FIRST and FOLLOW for the postfix grammar after removing the left recursion:$ S → S S+/ S S* /a$

jayanth

3.5k views

jayanth asked Jun 16, 2022

0 votes

1 answer

3

To get follow of grammar ,Should I remove left_recursion first?
S-> SS | Aa A->Sb | a (a) prove that the grammar is ambiguous. (b) find the follow for the grammar (c) then remove the left recursion from the grammar.

S- SS | AaA->Sb | a(a) prove that the grammar is ambiguous.(b) find the follow for the grammar(c) then remove the left recursion from the grammar.

Sara Wageh

1.2k views

Sara Wageh asked Dec 31, 2021

4 votes

1 answer

4

S->AA/ab A->Bd/null B->SB/d remove left recursion
S->AA/ab A->Bd/null B->SB/d remove left recursion

S->AA/ab A->Bd/null B->SB/dremove left recursion

vrajdobariya

1.2k views

vrajdobariya asked Sep 6, 2021

1 votes

1 answer

5

GATE Overflow Test Series | Compiler Design | Test 1 | Question: 18
Which of the following grammar is/are left-recursive? (Mark all the appropriate choices) $A \rightarrow B \mid a \mid CBD$ $B \rightarrow C\mid b$ $C \rightarrow A \mid c$ $D \rightarrow d$ $A \rightarrow Ba \mid C$ ... $S \rightarrow (L) \mid x$ $L \rightarrow SL'$ $L' \rightarrow \epsilon \mid ,SL'$

Which of the following grammar is/are left-recursive? (Mark all the appropriate choices)$A \rightarrow B \mid a \mid CBD$$B \rightarrow C\mid b$$C \rightarrow A \mid c$$D...

gatecse

150 views

gatecse asked Dec 14, 2020

1 votes

1 answer

6

Ullman (Compiler Design) Edition 2 Exercise 5.4 Question 3 (Page No. 337)
The following SDT computes the value of a string of $0's$ and $1's$ ... so the underlying grammar is not left recursive, and yet the same value of $B.val$ is computed for the entire input string.

The following SDT computes the value of a string of $0's$ and $1's$ interpreted as a positive, binary integer.$B\rightarrow B_{1}0\:\{B.val=2\times B_{1}.val\}\mid B_{1}1...

admin

2.1k views

admin asked Sep 6, 2019

1 votes

0 answers

7

Ullman (Compiler Design) Edition 2 Exercise 4.4 Question 1 (Page No. 231)
For each of the following grammars, devise predictive parsers and show the parsing tables. You may left-factor and/or eliminate left-recursion from your grammars first. $S\rightarrow 0S1\mid 01$ ... $bfactor\:\rightarrow\:not\:bfactor\mid (bexpr)\mid true\mid false$

For each of the following grammars, devise predictive parsers and show the parsing tables. You may left-factor and/or eliminate left-recursion from your grammars first. $...

admin

1.3k views

admin asked Aug 20, 2019

0 votes

0 answers

8

Ullman (Compiler Design) Edition 2 Exercise 4.3 Question 2 (Page No. 216 - 217)
Repeat Exercise 4.3.1 on the following grammars: $S\rightarrow SS+\mid SS\: \ast\mid a$ $S\rightarrow 0S1\mid 01$ $S\rightarrow S ( S ) S\mid \epsilon$ $S\rightarrow (L)\mid a$ ... $bterm\rightarrow bterm\:and\:bfactor\mid bfactor$ $bfactor\rightarrow not\: bfactor\mid ( bexpr )\mid true \mid false $

Repeat Exercise 4.3.1 on the following grammars:$S\rightarrow SS+\mid SS\: \ast\mid a$$S\rightarrow 0S1\mid 01$$S\rightarrow S ( S ) S\mid \epsilon$$S\rightarrow (L)\mid ...

admin

667 views

admin asked Aug 20, 2019

0 votes

0 answers

9

Ullman (Compiler Design) Edition 2 Exercise 4.3 Question 1 (Page No. 216)
The following is a grammar for regular expressions over symbols $a$ and $b$ only, using $+$ in place of $\mid$ for union, to avoid conflict with the use of vertical bar as a metasymbol in ... to left factoring, eliminate left recursion from the original grammar. Is the resulting grammar suitable for top-down parsing?

The following is a grammar for regular expressions over symbols $a$ and $b$ only, using $+$ in place of $\mid$ for union, to avoid conflict with the use of vertical bar a...

admin

1.6k views

admin asked Aug 20, 2019

0 votes

0 answers

10

Ullman(2e) Exercise-5.4.2 page no-336 Syntax Directed Translation
Rewrite the following SDT: A->A {a} B | AB {b} | 0 B->B {c} A | BA {d} | 1 so that the underlying grammar becomes non-left-recursive. Here a, b, c and d are actions, and 0 and 1 are terminals is my solution correct? A→ 0A’ A’→ {a} BA’ | B {b} A’ | ε B→ 1B’ B’→ {c} AB’ | A {d} B’ | ε

Rewrite the following SDT:A->A {a} B | AB {b} | 0B->B {c} A | BA {d} | 1so that the underlying grammar becomes non-left-recursive. Here a, b, c and d are actions, and 0 a...

aditi19

1.3k views

aditi19 asked Mar 29, 2019

0 votes

1 answer

11

Self doubt
We know that a grammar is contain 1-left recursive 2-ambiguous 3-Common prefix Then grammar is not LL(1) If let I constructed M-TABLE or PARSE TABLE of grammar which is not contain left recursive and common prefixes . Let consider I am not able to find out ... not , If LL(1) parse table contains multiple choice in same row and column then Can I said that grammar is ambiguous or not?

We know that a grammar is contain1-left recursive2-ambiguous3-Common prefixThen grammar is not LL(1) If let I constructed M-TABLE or PARSE TABLEof grammar which is not co...

Ashish RajAnand

437 views

Ashish RajAnand asked Feb 5, 2019

0 votes

1 answer

12

Ace Test Series: Compiler Design - Left Recursion Elimination

Shankar Kakde

1.6k views

Shankar Kakde asked Jan 23, 2019

1 votes

1 answer

13

Applied Course | Mock GATE | Test 1 | Question: 60
The left-factoring of the given CFG is $S \rightarrow aBcD \mid aBD \mid daB \mid d$ $B \rightarrow b$ $D \rightarrow d$ $S \rightarrow aBB' \mid d$ $B' \rightarrow cD \mid D$ $B \rightarrow b$ $D \rightarrow d$ ... $B' \rightarrow aB$ $B \rightarrow b$ $D \rightarrow d$ None of them

The left-factoring of the given CFG is$S \rightarrow aBcD \mid aBD \mid daB \mid d$$B \rightarrow b$$D \rightarrow d$$S \rightarrow aBB' \mid d$$B' \rightarrow cD \mid D$...

Applied Course

648 views

Applied Course asked Jan 16, 2019

0 votes

1 answer

14

UPPCL AE 2018:64
The following grammar $\text{G}$ is left recursive. $\text{E} \rightarrow \text{E + T}\; \mid \; \text{T} $ $\text{T} \rightarrow \text{T * F} \; \mid \; \text{F} $ $\text{F} \rightarrow \text{(E)} \mid \textbf{id} $ Which of the following is a ...

The following grammar $\text{G}$ is left recursive.$\text{E} \rightarrow \text{E + T}\; \mid \; \text{T} $$\text{T} \rightarrow \text{T * F} \; \mid \; \text{F} $$\text{F...

admin

365 views

admin asked Jan 5, 2019

1 votes

1 answer

15

Non-Left recursive grammar of the below grammar.
Grammar. S → Aa | B A → Ac | Aad | bd | epsilon . .

Grammar. S → Aa | B A → Ac | Aad | bd | epsilon . .

susgir2

952 views

susgir2 asked Jan 2, 2019

0 votes

0 answers

16

https://gateoverflow.in/1697/gate1998-6b
why isn't A replaced in the first production? that is also indirect recursive

why isn't A replaced in the first production? that is also indirect recursive

aditi19

397 views

aditi19 asked Oct 26, 2018

0 votes

0 answers

17

Left Recursion
Remove the Left Recursion from it : A -> B|a|CBD B -> C|b C -> A|c D -> d

Remove the Left Recursion from it : A - B|a|CBDB - C|bC - A|cD - d

Na462

402 views

Na462 asked Sep 19, 2018

2 votes

2 answers

18

Left recursion
In this question should we eliminate left recursion by putting values of S and A in the respective productions so answer will be c but if according to the given production than answer will be a how to solve?

In this question should we eliminate left recursion by putting values of S and A in the respective productions so answer will be c but if according to the given productio...

saumya mishra

1.7k views

saumya mishra asked Jun 11, 2018

0 votes

5 answers

19

Compiler desigb
consider the following grammar $E\rightarrow int|int+E|int-E |int-(E) |int*E$ Which statement is true? a) Grammer is left factored b) Cant be determined

consider the following grammar$E\rightarrow int|int+E|int-E |int-(E) |int*E$Which statement is true?a) Grammer is left factoredb) Cant be determined

Pun M

933 views

Pun M asked Apr 1, 2018

0 votes

1 answer

20

Check if grammar is LL(1) ?
Given a grammar : $E \rightarrow E + T / T$ $T \rightarrow i$ Can I directly say that grammar is not $LL(1)$ because $LL(1)$ can't parse Left Recursive Grammar, without drawing parsing table ?

Given a grammar :$E \rightarrow E + T / T$$T \rightarrow i$Can I directly say that grammar is not $LL(1)$ because $LL(1)$ can't parse Left Recursive Grammar, without dra...

Rahul Ranjan 1

5.0k views

Rahul Ranjan 1 asked Mar 19, 2018

0 votes

1 answer

21

Left Recursion Removal
Remove Left Recursion from the following Context Free Grammar. $S \rightarrow Aa| Sa|c$ $A \rightarrow Ab|Sd|e$

Remove Left Recursion from the following Context Free Grammar.$S \rightarrow Aa| Sa|c$$A \rightarrow Ab|Sd|e$

Mk Utkarsh

1.2k views

Mk Utkarsh asked Jan 31, 2018

3 votes

5 answers

22

MadeEasy Test Series 2018: Compiler Design - Left Recursion
I think the answer should be option: C but it is given option A. Providing the snapshot of the question with the options provided. I don't think option A should be the correct one, even if it then we cannot ... "bda" from option A which is possible in the original grammar. Please help with this question. Thanks in advance.

I think the answer should be option: C but it is given option A.Providing the snapshot of the question with the options provided.I don't think option A should be the corr...

nishitshah

1.6k views

nishitshah asked Jan 23, 2018

0 votes

1 answer

23

ambiguity
$E→E−T ∣ T$ $T→T/F ∣ F$ $F→(E) ∣ id$ (E is the start symbol) This grammar is unambiguous but shouldn't it be ambiguous because it has left recursion?

$E→E−T ∣ T$$T→T/F ∣ F$$F→(E) ∣ id$(E is the start symbol)This grammar is unambiguous but shouldn't it be ambiguous because it has left recursion?

A_i_$_h

652 views

A_i_$_h asked Dec 23, 2017

2 votes

2 answers

24

eliminate left recurrsion
Eliminate left recurrsion from $S\rightarrow S0S1S | 01$

Eliminate left recurrsion from $S\rightarrow S0S1S | 01$

A_i_$_h

904 views

A_i_$_h asked Oct 20, 2017

1 votes

2 answers

25

left recursion

Parshu gate

1.2k views

Parshu gate asked Sep 17, 2017

0 votes

1 answer

26

LEft recurssion
E -> E+T / T T -> id grammar after left recursion is a) E->T +E / T T ->id b)E ->T / E + T T ->id c) E->E' T T->+TE' / epsilon d)E ->TX X- > +TX / epsilon Actually it should be option c... ... T E'..the position of E and T is interchanged.in the option..........is that a pproblem??? the answer is given as option D can someone please help

E - E+T / TT - idgrammar after left recursion isa) E->T +E / T T ->idb)E ->T / E + TT ->idc) E->E' TT->+TE' / epsilond)E ->TXX- +TX / epsilonActually i...

A_i_$_h

352 views

A_i_$_h asked Sep 7, 2017

2 votes

0 answers

27

SELF DOUBT
Can we find FIRST and FOLLOW for a left recursive grammar?

Can we find FIRST and FOLLOW for a left recursive grammar?

Vivek Jain

780 views

Vivek Jain asked Aug 19, 2017

0 votes

1 answer

28

LEFT RECURSION
To avoid left recursion can we do like this. I think this is incorrect way to do

To avoid left recursion can we do like this. I think this is incorrect way to do

learner_geek

1.3k views

learner_geek asked Aug 5, 2017

tags	tag:apple
author	user:martin
title	title:apple
content	content:apple
exclude	-tag:apple
force match	+apple
views	views:100
score	score:10
answers	answers:2
is accepted	isaccepted:true
is closed	isclosed:true