Theory Of Computation MCQ - Context free languages

61:

If L1 = {x  | x is a palindrome in (0 + 1)*}
L2 = {letter (letter + digit)* };
L3 = (0n 1n 2n | n > 1}
L4 = {ambnam+n | m, n > 1}

then which of the following statement is incorrect ?

 A. L1 is context free language and L3 is context sensitive language B. L2 is a regular set and L4 is not a context free language C. Both L1 and L2 are regular sets D. Both L3 and L4 are context-sensitive languages Answer Report Discuss Option: A Explanation : Click on Discuss to view users comments. Kajal Kansal said: (3:51am on Wednesday 9th April 2014) L1 is surely cfl and l3 is csl then how this is the right answer.i think c is the right answer as L1 is not regular set because of palindrome Vandana said: (7:12pm on Thursday 15th February 2018) Only option A is true , rest all 3 are false , so in question they should ask for the correct answer. Then option A will be the right choice. Write your comments here:
62:

A grammar to generate
{ (ab)n I n ≥ 1 }  ∪  { (ba)n I n ≥ 1 }
is constructed as

 A. S ---> S1, S1 ---> abS1,  S1 ---> ab,  S ---> S2, S2 —> baS2, S2 —> ba B. S ---> S1 , Sl ---> aS1, S1 ---> ab, S ---> S2, S2 ---> bS2, S2 —> bc C. S —> S1,  S1—>S2, S2 —> S1a, S1 —> ab, S2 —> ba D. none of these Answer Report Discuss Option: C Explanation : Click on Discuss to view users comments. Write your comments here:
63:

Consider the grammar
S ---> PQ | SQ | PS
P ---> x
Q-->   y

To get a string of n terminals, the number of productions to be used is

 A. n2 B. n + 1 C. 2n D. 2n - 1 Answer Report Discuss Option: D Explanation : Click on Discuss to view users comments. Write your comments here:
64:

What is the highest type number which can be applied to the following grammar ?
S —> Aa, A —> Ba, B —> abc

 A. Type 0 B. Type 1 C. Type 2 D. Type 3 Answer Report Discuss Option: C Explanation : Click on Discuss to view users comments. Vandana said: (7:16pm on Thursday 15th February 2018) Given grammer is a left linear grammer , so it is type 3 grammer , so correct option should be option d. Write your comments here:
65:

Following syntax-directed translation scheme is used with a shift reduction (bottom up) parser that perform the action in braces immediately after a reduction by the corresponding production

A  —> aB  {print “(1)” A —> c {print “1”),
B —> Ab  {print *2”}.

When parser is aaacbbb, then string printed

 A. 0202021 B. 1202020 C. 1020202 D. none of these Answer Report Discuss Option: A Explanation : Click on Discuss to view users comments. Write your comments here:

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