Prove that NP is closed under karp reduction?Space(n) not closed under Karp reductions - what about...

How much RAM could one put in a typical 80386 setup?

Pattern match does not work in bash script

Smoothness of finite-dimensional functional calculus

Schoenfled Residua test shows proportionality hazard assumptions holds but Kaplan-Meier plots intersect

What are these boxed doors outside store fronts in New York?

Replacing matching entries in one column of a file by another column from a different file

TGV timetables / schedules?

Have astronauts in space suits ever taken selfies? If so, how?

Can I ask the recruiters in my resume to put the reason why I am rejected?

How is it possible to have an ability score that is less than 3?

Is it possible to do 50 km distance without any previous training?

Unknown notation: What do three bars mean?

How do we improve the relationship with a client software team that performs poorly and is becoming less collaborative?

Writing rule stating superpower from different root cause is bad writing

Is a tag line useful on a cover?

US citizen flying to France today and my passport expires in less than 2 months

Why don't electron-positron collisions release infinite energy?

Characters won't fit in table

Font hinting is lost in Chrome-like browsers (for some languages )

"to be prejudice towards/against someone" vs "to be prejudiced against/towards someone"

Why was the small council so happy for Tyrion to become the Master of Coin?

Why doesn't Newton's third law mean a person bounces back to where they started when they hit the ground?

tikz: show 0 at the axis origin

How old can references or sources in a thesis be?



Prove that NP is closed under karp reduction?


Space(n) not closed under Karp reductions - what about NTime(n)?Class P is closed under rotation?Prove or disprove that $NL$ is closed under polynomial many-one reductions$mathbf{NC_2}$ is closed under log-space reductionOn Karp reductionwhen can I know if a class (complexity) is closed under reduction (cook/karp)Check if class $PSPACE$ is closed under polyonomially space reductionIs NPSPACE also closed under polynomial-time reduction and under log-space reduction?Prove PSPACE is closed under complement?Prove PSPACE is closed under union?













1












$begingroup$


A complexity class $mathbb{C}$ is said to be closed under a reduction if:



$A$ reduces to $B$ and $B in mathbb{C}$ $implies$ $A in mathbb{C}$



How would you go about proving this if $mathbb{C} = NP$ and the reduction to be the karp reduction? i.e.



Prove that if $A$ karp reduces to $B$ and $B in NP$ $implies$ $A in NP$










share|cite|improve this question







New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$








  • 2




    $begingroup$
    Try using the definitions.
    $endgroup$
    – Yuval Filmus
    2 hours ago










  • $begingroup$
    @YuvalFilmus thanks for the advice, this helped me figure it out!
    $endgroup$
    – Ankit Bahl
    1 hour ago
















1












$begingroup$


A complexity class $mathbb{C}$ is said to be closed under a reduction if:



$A$ reduces to $B$ and $B in mathbb{C}$ $implies$ $A in mathbb{C}$



How would you go about proving this if $mathbb{C} = NP$ and the reduction to be the karp reduction? i.e.



Prove that if $A$ karp reduces to $B$ and $B in NP$ $implies$ $A in NP$










share|cite|improve this question







New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$








  • 2




    $begingroup$
    Try using the definitions.
    $endgroup$
    – Yuval Filmus
    2 hours ago










  • $begingroup$
    @YuvalFilmus thanks for the advice, this helped me figure it out!
    $endgroup$
    – Ankit Bahl
    1 hour ago














1












1








1





$begingroup$


A complexity class $mathbb{C}$ is said to be closed under a reduction if:



$A$ reduces to $B$ and $B in mathbb{C}$ $implies$ $A in mathbb{C}$



How would you go about proving this if $mathbb{C} = NP$ and the reduction to be the karp reduction? i.e.



Prove that if $A$ karp reduces to $B$ and $B in NP$ $implies$ $A in NP$










share|cite|improve this question







New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




A complexity class $mathbb{C}$ is said to be closed under a reduction if:



$A$ reduces to $B$ and $B in mathbb{C}$ $implies$ $A in mathbb{C}$



How would you go about proving this if $mathbb{C} = NP$ and the reduction to be the karp reduction? i.e.



Prove that if $A$ karp reduces to $B$ and $B in NP$ $implies$ $A in NP$







complexity-theory






share|cite|improve this question







New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|cite|improve this question







New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|cite|improve this question




share|cite|improve this question






New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 2 hours ago









Ankit BahlAnkit Bahl

262




262




New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.








  • 2




    $begingroup$
    Try using the definitions.
    $endgroup$
    – Yuval Filmus
    2 hours ago










  • $begingroup$
    @YuvalFilmus thanks for the advice, this helped me figure it out!
    $endgroup$
    – Ankit Bahl
    1 hour ago














  • 2




    $begingroup$
    Try using the definitions.
    $endgroup$
    – Yuval Filmus
    2 hours ago










  • $begingroup$
    @YuvalFilmus thanks for the advice, this helped me figure it out!
    $endgroup$
    – Ankit Bahl
    1 hour ago








2




2




$begingroup$
Try using the definitions.
$endgroup$
– Yuval Filmus
2 hours ago




$begingroup$
Try using the definitions.
$endgroup$
– Yuval Filmus
2 hours ago












$begingroup$
@YuvalFilmus thanks for the advice, this helped me figure it out!
$endgroup$
– Ankit Bahl
1 hour ago




$begingroup$
@YuvalFilmus thanks for the advice, this helped me figure it out!
$endgroup$
– Ankit Bahl
1 hour ago










1 Answer
1






active

oldest

votes


















2












$begingroup$

I was able to figure it out. In case anyone was wondering:



$B in NP$ means that there exists a non-deterministic polynomial time algorithm for $B$. Let's call that $b(i)$, where i is the input to $B$.



$A$ karp reducing to $B implies$ that there exists a function $m$ such that $m$ can take an input $i$ to $A$ and map it to some input $m(i)$ for $B$, and if an instance of $i$ is true for $A$ then $m(i)$ is true for B (and vice versa),



Therefore, an algorithm for $A$ can be made as follows:



$A (i)$




  1. Take input $i$ and apply $m$ to yield $m(i)$

  2. Apply $b$ with input $m(i)$


This yields an output for $A$. Since both $m$ and $b$ are non-deterministic polynomial time, this algorithm is non-deterministic polynomial time. Therefore $A$ must be in NP.






share|cite|improve this answer








New contributor




Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






$endgroup$














    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: "419"
    };
    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: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    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
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });






    Ankit Bahl is a new contributor. Be nice, and check out our Code of Conduct.










    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcs.stackexchange.com%2fquestions%2f106574%2fprove-that-np-is-closed-under-karp-reduction%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









    2












    $begingroup$

    I was able to figure it out. In case anyone was wondering:



    $B in NP$ means that there exists a non-deterministic polynomial time algorithm for $B$. Let's call that $b(i)$, where i is the input to $B$.



    $A$ karp reducing to $B implies$ that there exists a function $m$ such that $m$ can take an input $i$ to $A$ and map it to some input $m(i)$ for $B$, and if an instance of $i$ is true for $A$ then $m(i)$ is true for B (and vice versa),



    Therefore, an algorithm for $A$ can be made as follows:



    $A (i)$




    1. Take input $i$ and apply $m$ to yield $m(i)$

    2. Apply $b$ with input $m(i)$


    This yields an output for $A$. Since both $m$ and $b$ are non-deterministic polynomial time, this algorithm is non-deterministic polynomial time. Therefore $A$ must be in NP.






    share|cite|improve this answer








    New contributor




    Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.






    $endgroup$


















      2












      $begingroup$

      I was able to figure it out. In case anyone was wondering:



      $B in NP$ means that there exists a non-deterministic polynomial time algorithm for $B$. Let's call that $b(i)$, where i is the input to $B$.



      $A$ karp reducing to $B implies$ that there exists a function $m$ such that $m$ can take an input $i$ to $A$ and map it to some input $m(i)$ for $B$, and if an instance of $i$ is true for $A$ then $m(i)$ is true for B (and vice versa),



      Therefore, an algorithm for $A$ can be made as follows:



      $A (i)$




      1. Take input $i$ and apply $m$ to yield $m(i)$

      2. Apply $b$ with input $m(i)$


      This yields an output for $A$. Since both $m$ and $b$ are non-deterministic polynomial time, this algorithm is non-deterministic polynomial time. Therefore $A$ must be in NP.






      share|cite|improve this answer








      New contributor




      Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      $endgroup$
















        2












        2








        2





        $begingroup$

        I was able to figure it out. In case anyone was wondering:



        $B in NP$ means that there exists a non-deterministic polynomial time algorithm for $B$. Let's call that $b(i)$, where i is the input to $B$.



        $A$ karp reducing to $B implies$ that there exists a function $m$ such that $m$ can take an input $i$ to $A$ and map it to some input $m(i)$ for $B$, and if an instance of $i$ is true for $A$ then $m(i)$ is true for B (and vice versa),



        Therefore, an algorithm for $A$ can be made as follows:



        $A (i)$




        1. Take input $i$ and apply $m$ to yield $m(i)$

        2. Apply $b$ with input $m(i)$


        This yields an output for $A$. Since both $m$ and $b$ are non-deterministic polynomial time, this algorithm is non-deterministic polynomial time. Therefore $A$ must be in NP.






        share|cite|improve this answer








        New contributor




        Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
        Check out our Code of Conduct.






        $endgroup$



        I was able to figure it out. In case anyone was wondering:



        $B in NP$ means that there exists a non-deterministic polynomial time algorithm for $B$. Let's call that $b(i)$, where i is the input to $B$.



        $A$ karp reducing to $B implies$ that there exists a function $m$ such that $m$ can take an input $i$ to $A$ and map it to some input $m(i)$ for $B$, and if an instance of $i$ is true for $A$ then $m(i)$ is true for B (and vice versa),



        Therefore, an algorithm for $A$ can be made as follows:



        $A (i)$




        1. Take input $i$ and apply $m$ to yield $m(i)$

        2. Apply $b$ with input $m(i)$


        This yields an output for $A$. Since both $m$ and $b$ are non-deterministic polynomial time, this algorithm is non-deterministic polynomial time. Therefore $A$ must be in NP.







        share|cite|improve this answer








        New contributor




        Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
        Check out our Code of Conduct.









        share|cite|improve this answer



        share|cite|improve this answer






        New contributor




        Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
        Check out our Code of Conduct.









        answered 1 hour ago









        Ankit BahlAnkit Bahl

        262




        262




        New contributor




        Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
        Check out our Code of Conduct.





        New contributor





        Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
        Check out our Code of Conduct.






        Ankit Bahl is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
        Check out our Code of Conduct.






















            Ankit Bahl is a new contributor. Be nice, and check out our Code of Conduct.










            draft saved

            draft discarded


















            Ankit Bahl is a new contributor. Be nice, and check out our Code of Conduct.













            Ankit Bahl is a new contributor. Be nice, and check out our Code of Conduct.












            Ankit Bahl is a new contributor. Be nice, and check out our Code of Conduct.
















            Thanks for contributing an answer to Computer Science 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%2fcs.stackexchange.com%2fquestions%2f106574%2fprove-that-np-is-closed-under-karp-reduction%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

            “%fieldName is a required field.”, in Magento2 REST API Call for GET Method Type The Next...

            How to change City field to a dropdown in Checkout step Magento 2Magento 2 : How to change UI field(s)...

            夢乃愛華...