Which of the following language is not context free?
Which of the following language is not context free?
An expression that doesn’t form a pattern on which linear comparison could be carried out using stack is not context free language. Example 1 – L = { a^m b^n^2 } is not context free. Example 2 – L = { a^n b^2^n } is not context free.
Which of the following languages are context free language?
Which of the following languages are context-free? Explanation: L1 is CFL because there is only one comparison at a time.
How do you prove that a language is not context free using pumping lemma?
The pumping lemma is often used to prove that a given language L is non-context-free, by showing that arbitrarily long strings s are in L that cannot be “pumped” without producing strings outside L. . This contradicts the definition of L. Therefore, our initial assumption that L is context free must be false.
What makes a language context-free?
A valid (accepted) sentence in the language must follow particular rules, the grammar. A context-free language is a language generated by a context-free grammar. They are more general (and include) regular languages. The same context-free language might be generated by multiple context-free grammars.
How do you find language context free grammar?
A language is context-free if it is generated by a CFG. For compactness, we write S → 0S1 | ε where the vertical bar means or. Let P be language of palindromes with alpha- bet {a,b}. One can determine a CFG for P by finding a recursive decomposition.
Are all regular languages Context free?
All regular languages are context-free languages, but not all context-free languages are regular. Most arithmetic expressions are generated by context-free grammars, and are therefore, context-free languages.
Is WW a context free language?
It’s a context sensitive language. wwr is context free because you can use a pda to compare the first alphabet of wr with the last alphabet of w. But in case of ww you cannot do any comparison because only the last alphabet of first w is on top of stack.
Which of the following languages are context free L1 a MB NA NB M ⎪ m n ≥ 1 L2 A mb NA MB n ⎪ m n ≥ 1 L3 A MB N ⎪ M 2n 1 answer?
Discussion Forum
| Que. | Which of the following languages are context-free? L1 = {a^m b^n a^n b^m ⎪ m, n ≥ 1} L2 = {a^m b^n a^m b^n ⎪ m, n ≥ 1} L3 = {a^m b^n ⎪ m = 2n + 1} |
|---|---|
| b. | L1 and L3 only |
| c. | L2 and L3 only |
| d. | L3 only |
| Answer:L1 and L3 only |
Which of the following does not obey pumping lemma for context free languages?
Explanation: Finite languages (which are regular hence context free ) obey pumping lemma where as unrestricted languages like recursive languages do not obey pumping lemma for context free languages.
What does the pumping lemma prove?
The pumping lemma is often used to prove that a particular language is non-regular: a proof by contradiction may consist of exhibiting a string (of the required length) in the language that lacks the property outlined in the pumping lemma.
Are all languages context-free?
