Finding languages such that $L_{1} subseteq L_{2} subseteq L_{3}$ where $L_{1}, L_{3} notin mathbb{R}$,...












0












$begingroup$


I am struggling to find such languages $L_{1}$, $L_{2}$, and $L_{3}$ such that
$$
L_{1} subseteq L_{2} subseteq L_{3}
$$

where $L_{1}, L_{3} notin mathbb{R}$ and $L_{2} in mathbb{R}$.



I know they exist, I need help finding them.










share|cite|improve this question











$endgroup$












  • $begingroup$
    What does $Bbb R$ mean here?
    $endgroup$
    – MJD
    Jan 10 at 21:39
















0












$begingroup$


I am struggling to find such languages $L_{1}$, $L_{2}$, and $L_{3}$ such that
$$
L_{1} subseteq L_{2} subseteq L_{3}
$$

where $L_{1}, L_{3} notin mathbb{R}$ and $L_{2} in mathbb{R}$.



I know they exist, I need help finding them.










share|cite|improve this question











$endgroup$












  • $begingroup$
    What does $Bbb R$ mean here?
    $endgroup$
    – MJD
    Jan 10 at 21:39














0












0








0





$begingroup$


I am struggling to find such languages $L_{1}$, $L_{2}$, and $L_{3}$ such that
$$
L_{1} subseteq L_{2} subseteq L_{3}
$$

where $L_{1}, L_{3} notin mathbb{R}$ and $L_{2} in mathbb{R}$.



I know they exist, I need help finding them.










share|cite|improve this question











$endgroup$




I am struggling to find such languages $L_{1}$, $L_{2}$, and $L_{3}$ such that
$$
L_{1} subseteq L_{2} subseteq L_{3}
$$

where $L_{1}, L_{3} notin mathbb{R}$ and $L_{2} in mathbb{R}$.



I know they exist, I need help finding them.







computability formal-languages automata turing-machines






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 9 at 1:51









amWhy

1




1










asked Jan 8 at 23:47









Tomer LevyTomer Levy

406




406












  • $begingroup$
    What does $Bbb R$ mean here?
    $endgroup$
    – MJD
    Jan 10 at 21:39


















  • $begingroup$
    What does $Bbb R$ mean here?
    $endgroup$
    – MJD
    Jan 10 at 21:39
















$begingroup$
What does $Bbb R$ mean here?
$endgroup$
– MJD
Jan 10 at 21:39




$begingroup$
What does $Bbb R$ mean here?
$endgroup$
– MJD
Jan 10 at 21:39










1 Answer
1






active

oldest

votes


















0












$begingroup$

Any language $L$ over a finite alphabet $Sigma$ is both contained in some regular language and in some non-regular language.



Firstly, $Sigma^*$ is regular and contains the language.



Secondly, if $x,ynotinSigma$, then ${sx^ny^n:sin L,ninmathbb{N}}$ is non-regular and contains $L$. The standard proof that ${x^ny^n:ninmathbb{N}}$ is non-regular using the pumping lemma can be copied completely to prove this.






share|cite|improve this answer









$endgroup$













    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "69"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3066878%2ffinding-languages-such-that-l-1-subseteq-l-2-subseteq-l-3-where-l-1%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    0












    $begingroup$

    Any language $L$ over a finite alphabet $Sigma$ is both contained in some regular language and in some non-regular language.



    Firstly, $Sigma^*$ is regular and contains the language.



    Secondly, if $x,ynotinSigma$, then ${sx^ny^n:sin L,ninmathbb{N}}$ is non-regular and contains $L$. The standard proof that ${x^ny^n:ninmathbb{N}}$ is non-regular using the pumping lemma can be copied completely to prove this.






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      Any language $L$ over a finite alphabet $Sigma$ is both contained in some regular language and in some non-regular language.



      Firstly, $Sigma^*$ is regular and contains the language.



      Secondly, if $x,ynotinSigma$, then ${sx^ny^n:sin L,ninmathbb{N}}$ is non-regular and contains $L$. The standard proof that ${x^ny^n:ninmathbb{N}}$ is non-regular using the pumping lemma can be copied completely to prove this.






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        Any language $L$ over a finite alphabet $Sigma$ is both contained in some regular language and in some non-regular language.



        Firstly, $Sigma^*$ is regular and contains the language.



        Secondly, if $x,ynotinSigma$, then ${sx^ny^n:sin L,ninmathbb{N}}$ is non-regular and contains $L$. The standard proof that ${x^ny^n:ninmathbb{N}}$ is non-regular using the pumping lemma can be copied completely to prove this.






        share|cite|improve this answer









        $endgroup$



        Any language $L$ over a finite alphabet $Sigma$ is both contained in some regular language and in some non-regular language.



        Firstly, $Sigma^*$ is regular and contains the language.



        Secondly, if $x,ynotinSigma$, then ${sx^ny^n:sin L,ninmathbb{N}}$ is non-regular and contains $L$. The standard proof that ${x^ny^n:ninmathbb{N}}$ is non-regular using the pumping lemma can be copied completely to prove this.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 9 at 0:04









        SmileyCraftSmileyCraft

        3,566517




        3,566517






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Mathematics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3066878%2ffinding-languages-such-that-l-1-subseteq-l-2-subseteq-l-3-where-l-1%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            MongoDB - Not Authorized To Execute Command

            How to fix TextFormField cause rebuild widget in Flutter

            in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith