CS402 MCQs Lectures 35-45

CS402 MCQs lecture 35 to 45

1) L= language of words containing even number of a’s. Regular Expression is

(b+ab*a)*

a+bb*aab*a (a+b)*ab(a+b)*

2. The regular expression defining the language L1 U L2 can be obtained, converting and reducing the previous ------------- into a ---- -------- as after eliminating states.

GTG, TG

FA, GTG

FA, TG TG, RE

3. The language that can be expressed by any regular expression is called a Non regular language.
4. The languages -------------- are the examples of non regular languages.

PALINDROME and PRIME · PALINDROME and EVEN-EVEN · EVEN-EVEN and PRIME · FACTORIAL and SQURE

5. Let L be any infinite regular language, defined over an alphabet Σ then there exist three strings x, y and z belonging to Σ* such that all the strings of the form [IMG]file:///C:/DOCUME%7E1/ADMINI%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_i mage009.gif[/IMG]for n=1,2,3, … are the words in L. called.

Complement of L

Pumping Lemma

Kleene’s theorem None in given (6) Languages are proved to be regular or non regular using pumping lemma. (7) ------------------- is obviously infinite language. EQUAL-EQUAL EVEN-EVEN

PALINDROME

FACTORIAL

(8) If, two strings x and y, defined over Σ, are run over an FA accepting the language L, then x and y are said to belong to the same class if they end in the same state, no matter that state is final or not.

(9) Myhill Nerode theorem is consisting of the followings,

L partitions Σ* into distinct classes. If L is regular then, L generates finite number of classes. If L generates finite number of classes then L is regular.

(10) The language Q is said to be quotient of two regular languages P and R, denoted by--- if PQ=R. R=Q/P Q=R/P Q=P/R P=R/Q

(11) If two languages R and Q are given, then the prefixes of Q in R denoted by Pref(Q in R).

(12) Let Q = {aa, abaaabb, bbaaaaa, bbbbbbbbbb} and R = {b, bbbb, bbbaaa, bbbaaaaa} Pref (Q in R) is equal to,

{b,bbba,bbbaaa}

{b,bba,bbaaa} {ab,bba,bbbaa} {b,bba,bbba}

(13) If R is regular language and Q is any language (regular/ non regular), then Pref (Q in R) is ---------.

Non-regular Equal

Regular

Infinite

(14) "CFG" stands for _________

Context Free Graph

Context Free Grammar

Context Finite Graph Context Finite Grammar

(15) ___________ states are called the halt states.

ACCEPT and REJECT

ACCEPT and READ ACCEPT AND START ACCEPT AND WRITE

(16) The part of an FA, where the input string is placed before it is run, is called _______

State Transition

Input Tape

Output Tape

(17) In new format of an FA (discussed in lecture 37), This state is like dead-end non final state

ACCEPT

REJECT

STATR READ

(18) For language L defined over {a, b}, then L partitions {a, b}* into …… classes

Infinite Finite

Distinct

Non-distinct