How many strings of length less than 4 contains the language described by the regular expression (x+y)*y(a+ab)*?
String of length 0 = 1
string of length 1 = 4
string of length 2 = 3
string of length 3 = 3.
Which of the following is true?
None.
A language is regular if and only if
All of above machine can accept regular language but all string accepted by machine is regular only for DFA.
Regular grammar is
Regular grammar is subset of context free grammar.
Which of the following is not a regular expression?
Except b all are regular expression*.
Regular expression are
According to Chomsky hierarchy .
Which of the following is true?
None.
L and ~L are recursive enumerable then L is
If L is recursive enumerable and its complement too if and only if L is recursive.
Regular expressions are closed under
According to definition of regular expression.
Consider the production of the grammar S>AA A>aa A>bb Describe the language specified by the production grammar.
The production rules give aaaa or aabb or bbaa or bbbb.
Give a production grammar that specified language L = {ai b2i >= 1}
Let R1 and R2 be regular sets defined over alphabet ∑ then
Union of 2 regular languages is regular.
Which of the following String can be obtained by the language L = {ai b2i / i >=1}
Above production rule gives suppose if 3 a’s the corresponding b’s are 6 b’s.
Give a production grammar for the language L = {x/x ∈ (a,b)*, the number of a’s in x is multiple of 3}.
The above given condition is satisfied by
S>bS S>B
S>aA s>bA A>aB B>bB
B>aS S>a.
The production Grammar is {S>aSbb, S>abb} is
Type 2 grammar satisfies this production grammar.






