Q. String generated by
S->aS/bA,
A->d/ccA

View solution

Q. Consider the production of the grammar S->AA A->aa A->bb Describe the language specified by the production grammar.

View solution

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

View solution

Q. Regular expression a/b denotes the set

View solution

Q. In regular expressions, the operator ‘*’ stands for

View solution

Q. Find the pair of regular expressions that are equivalent

View solution

Q. Consider alphabet ∑ = {0, 1}, the null/empty string λ and the sets of strings X0, X1 and X0.How are X1 and X2 are related ?

X0 = 1 X1
X1 = 0 X1 + 1 X2
X2 = 0 X1 + {λ}

Which one of the following represents the strings in X0?

View solution

Q. Which of the following pairs of regular expression are equivalent?

View solution

Q. Which of the following identity is true?

View solution

Q. The set of all strings over ∑ = {a,b} in which all strings having bbbb as substring is

View solution

Q. The set of all strings over ∑ ={a,b} in which a single a is followed by any number of b’s a single b followed by any number of a’s is

View solution

Q. Regular expressions are used to represent which language

View solution

Q. The set of all strings over ∑ = {a,b} in which strings consisting a’s and b’s and ending with in bb is

View solution

Q. If P, Q, R are three regular expressions and if P does not contain a then the equation R = R + RP has a unique solution given by

View solution

Q. Which of the following regular expression denotes zero or more instances of an a or b?

View solution

Q. The string (a)|((b)*(c)) is equivalent to

View solution

Q. How many strings of length less than 4 contains the language described by the regular expression (x+y)*y(a+ab)* ?

View solution

Q. Which of the following is true ?

View solution

Q. Let the class of language accepted by finite state machine be L1 and the class of languages represented by regular expressions be L2 then

View solution

Q. Which of the following is not a regular expression?

View solution