A language is regular if and only if

Related Questions

• Let P be a regular language and Q be context-free language such that Q ∈ P. (For example, let P be the language represented by the regular expression p*q* and Q be {pnqn n∈ N}). Then which of the following is ALWAYS regular?
• Which of the following are decidable? 1) Whether the intersection of two regular language is infinite. 2) Whether a given context free language is regular. 3) Whether two push down automata accept the same language. 4) Whether a given grammar is context free.
• A language is represented by a regular expression (a)*(a + ba). Which of the following strings does not belong to the regular set represented by the above expression?
• If L1 and L2 are context free language and R a regular set, then which one of the languages below is not necessarily a context free language?
• Which of the following is true with respect to Kleene’s theorem? 1 A regular language is accepted by a finite automaton. 2 Every language is accepted by a finite automaton or a turingmachine.
• Consider the regular language L = (111+111111)*. The minimum number of states inany DFA accepting this language is
• Languages are proved to be regular or non regular using pumping lemma.
• Let S and T be language over ={a,b} represented by the regular expressions (a+b*)* and (a+b)*, respectively. Which of the following is true?
• Let the class of language accepted by finite state machine be L1 and the class of languages represented by regular expressions be L2 then
• Consider a string s over (0+1)*. The number of 0’s in s is denoted by no(s) and the number of 1’s in s is denoted by n1(s). The language that is not regular is