I have a question regarding regular languages. Given that $L_1$ and $L_2$ are non-regular languages, can a regular language $L$ exist so it is a subset of $L_2$ and $L_1$ subset of $L$?

To be more specific:

$\qquad L_1 \subset L \subset L_2$

for $L_1, L_2$ non-regular Languages.

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    $\begingroup$ Do you mean $\subseteq$ or $\subsetneq$? Do we know $L_1 \subseteq L_2$? And: What have to tried, where did you get stuck? $\endgroup$ – Raphael Feb 12 '14 at 7:56

Hint. Given any sets $A, B, C$ we have $A \cap C \subset C \subset B \cup C$.

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  • $\begingroup$ Thx for you answer you really guided to the solution! $\endgroup$ – Mario Feb 11 '14 at 19:29
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    $\begingroup$ Might be interesting to give languages $A \cap C, B \cup C, C$ that fulfill the desired properties. $\endgroup$ – G. Bach Feb 11 '14 at 20:32
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    $\begingroup$ Please consider not to encourage undesired posting behaviour. $\endgroup$ – Raphael Feb 12 '14 at 8:29

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