# Download GTU B.Tech 2020 Summer 6th Sem 2160704 Theory Of Computation Question Paper

Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Summer 6th Sem 2160704 Theory Of Computation Previous Question Paper

Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER? VI EXAMINATION ? SUMMER 2020
Subject Code: 2160704 Date:28/10/2020
Subject Name: THEORY OF COMPUTATION
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) What is a proposition? Which logical connectives do we use to generate 03
compound proposition?

(b) Out of these two statements which one is true and which is false. Justify your 04
1. ((( - )2 < 4 ))
2. ((( - )2 < 4 ))

(c) Develop an FA corresponding to following regular expression
07
= (11 + 110)0
Explain the properties of Distinguishability of Strings and Equivalence
classes, show minimum numbers of states necessary for this FA.

Q.2 (a) Write the strong principle of mathematical induction and show that () is 03
true for every 2, where () is the statement: n is either a prime or a
product of two or more primes.

(b) Define a CFG for language having strings with equal number of 0's and 1's. 04
= { {0,1} | 0() = 1()}

(c) L1 is a language over {0, 1}* that accepts strings ending in 11. L2 is a 07
language over {0, 1}* that accepts strings containing 101 as sub-string. Write
the regular expressions, draw FA for L1 and L2 and derive FA for L1 U L2.

OR

(c) Apply the subset construction technique to convert the given NFA to FA.
07
1

Q.3 (a) What is an Ambiguous CFG? Explain with reference to dangling else 03
problem.

(b) Explain Moore machine and Mealy machine. Give example of two 04
equivalent machines of each type performing similar function.

(c) Derive a CFG equivalent to following regular expression
07

(011 + 1)(01)

OR

Q.3 (a) What are Nullable variable in a CFG? How can we remove them from a 03
production?

(b) Draw NFA- for ((0+1)*10 + (00)*(11)*)*
04

(c) What are the steps to convert a CFG to Chomsky Normal Form?
07

Q.4 (a) Define a Turing Machine.
03

(b) What language will be generated by this CFG:
04
S aT | bT |
T aS | bS

(c) Develop a DPDA that accepts following language:
07
= { {, } |() > ()}

OR

Q.4 (a) What is the difference between accepting a Language and Recognizing a 03
Language?

(b) Give transition tables for PDA recognizing the language of all non- 04
palindromes over {a,b}*

(c) Write the pumping lemma for Context-Free Languages and prove that = 07
{ | 1} is not a CFL.

Q.5 (a) Define Primitive Recursive Functions.
03

(b) Draw a Turing Machine to accept a regular language
04
{a, b}*{aba}

(c) Develop a Turing Machine to accept even length palindromes over {a,b}*
07

OR
Q.5 (a) Define Bounded Minimalization of a predicate P.
03
(b) What important points do we derive from Church-Turing thesis?
04
(c) Develop a Turing Machine that creates a copy of its input string to the right 07
of the input but with a blank space separating the copy from the original.

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