Questions tagged [linear-languages]
7 questions
6
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1 answer
Closure properties of linear context-free languages
Under what operations are linear context-free languages closed? Suppose $L_1, L_2$ are two linear context free languages. Are there any guarantees about $L_1 \cup L_2$, $L_1 \cap L_2$, $\overline{L_1}$, $L_1 . L_2$, etc.?
anand nayak
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Pumping lemma for linear languages
Let $L$ be a linear language. Then there is a constant $p$ such that for all $w$ in $L$ with $|w| \ge p$, $w$ can be written as $uvxyz$ where (i) $|uvyz| \le p$ (ii) $|vy| > 0$ (iii) $uv^ixy^iz$ is in $L$, for all $i \ge 0$. How do I prove the first…
Arka Pal
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Is there a linear language $L$ such that $\overline{L} \in \texttt{Type-2} \setminus \texttt{Lin}$?
This question is kind of a follow-up to a question asked a few days ago.
Both of the non-linear complements of linear languages found were also not context free.
So the question is this: Is there some linear $L$ such that $\overline{L}$ is…
Knogger
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Why is the distinction between linear and context-free grammars useful?
The linear grammar is a grammar that's either left, right or left and right linear.
The context-free grammar can contain any kind of productions of non-terminals and terminals.
All linear grammars are context-free grammars.
But what is useful about…
mavavilj
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The complement of a particular language
We know that Linear context-free languages are not closed under complement, so I encountered a challenge in finding an example to show the above theorem. I think the complement of $L={a^nb^n}$ is not linear, but I can't prove it.
ErroR
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Greibach Normal Form of Linear Language
I was trying to get an arbitrary linear language to its GNF, and I converted it into one where all the productions were of the form $A\to Ba, A\to aB, A\to a$.
In this question, the accepted answer shows a way of converting some productions of a…
LeviathanTheEsper
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Prove $\{xy \mid |x|=|y|, x \neq y\}$ is not a linear language
Show the language
$$L = \{xy \mid |x| = |y|, x\neq y\}$$
is not linear.
I've seen and proved a pumping lemma for linear languages, mentioned here:
If $L$ is linear then there exists a constant $p$ such that for all $w \in L$ with $|w| \ge p$…
User584322
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