Context free grammar is not closed under

Related MCQs

• 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.
• Consider the following statements I. Recursive languages are closed under complementation II. Recursively enumerable languages are closed under union III. Recursively enumerable languages are closed under complementation Which of the above statement are TRUE?
• Which of the following statements is/are FALSE? (1) For every non-deterministic Turing machine, there exists an equivalent deterministic Turing machine. (2) Turing recognizable languages are closed under union and complementation. (3) Turing decidable languages are closed under intersection and complementation (4) Turing recognizable languages are closed under union and intersection.
• 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?
• Consider the following statements about the context free grammar G = {S - >SS,S - >ab,S ->ba, S - ε} I. G is ambiguous II. G produces all strings with equal number of a’s and b’s III. G can be accepted by a deterministic PDA. Which combination below expresses all the true statements about G?
• Context free grammar is used for-
• 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?
• The Family of recursive language is not closed under which of the following operations:
• Recursively enumerable languages are not closed under
• Recursively enumerable languages are not closed under: