Is ∅ ∈ { {∅} } true?












1












$begingroup$


If $ {emptyset} ∈ {emptyset,{emptyset}} $ is true, does it mean this $ emptyset in {{emptyset}} $ true ? If it is not, why it is false?



Also, does $ {{emptyset}}$ mean ${emptyset,{emptyset,{emptyset}}}$ ?










share|cite|improve this question









New contributor




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







$endgroup$

















    1












    $begingroup$


    If $ {emptyset} ∈ {emptyset,{emptyset}} $ is true, does it mean this $ emptyset in {{emptyset}} $ true ? If it is not, why it is false?



    Also, does $ {{emptyset}}$ mean ${emptyset,{emptyset,{emptyset}}}$ ?










    share|cite|improve this question









    New contributor




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







    $endgroup$















      1












      1








      1





      $begingroup$


      If $ {emptyset} ∈ {emptyset,{emptyset}} $ is true, does it mean this $ emptyset in {{emptyset}} $ true ? If it is not, why it is false?



      Also, does $ {{emptyset}}$ mean ${emptyset,{emptyset,{emptyset}}}$ ?










      share|cite|improve this question









      New contributor




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







      $endgroup$




      If $ {emptyset} ∈ {emptyset,{emptyset}} $ is true, does it mean this $ emptyset in {{emptyset}} $ true ? If it is not, why it is false?



      Also, does $ {{emptyset}}$ mean ${emptyset,{emptyset,{emptyset}}}$ ?







      elementary-set-theory






      share|cite|improve this question









      New contributor




      J.S 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




      J.S 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








      edited 1 hour ago









      user549397

      1,2221315




      1,2221315






      New contributor




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









      asked 1 hour ago









      J.SJ.S

      62




      62




      New contributor




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





      New contributor





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






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






















          1 Answer
          1






          active

          oldest

          votes


















          6












          $begingroup$

          The notation $a in A$ says that among the elements of $A$ there is one element that is exactly equal to $a.$



          The notation ${emptyset, {emptyset}}$ describes a set with exactly two elements.



          The first element is $emptyset.$ The second element is ${emptyset}.$
          Is one of those two elements exactly equal to ${emptyset}$?



          The notation ${ {emptyset}}$ describes a set with one element.
          That element is ${emptyset}.$



          Which element of ${ {emptyset}}$ do you think is exactly equal to $emptyset$?
          Hint: there's only one element you have to check.



          The notation ${emptyset, {emptyset, {emptyset}}}$ again describes a set with two elements.
          One element is $emptyset$ and the other is
          ${emptyset, {emptyset}}.$
          So this is definitely not the same thing as any set that has only one element.






          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
            });


            }
            });






            J.S 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%2fmath.stackexchange.com%2fquestions%2f3081469%2fis-%25e2%2588%2585-%25e2%2588%2588-%25e2%2588%2585-true%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









            6












            $begingroup$

            The notation $a in A$ says that among the elements of $A$ there is one element that is exactly equal to $a.$



            The notation ${emptyset, {emptyset}}$ describes a set with exactly two elements.



            The first element is $emptyset.$ The second element is ${emptyset}.$
            Is one of those two elements exactly equal to ${emptyset}$?



            The notation ${ {emptyset}}$ describes a set with one element.
            That element is ${emptyset}.$



            Which element of ${ {emptyset}}$ do you think is exactly equal to $emptyset$?
            Hint: there's only one element you have to check.



            The notation ${emptyset, {emptyset, {emptyset}}}$ again describes a set with two elements.
            One element is $emptyset$ and the other is
            ${emptyset, {emptyset}}.$
            So this is definitely not the same thing as any set that has only one element.






            share|cite|improve this answer









            $endgroup$


















              6












              $begingroup$

              The notation $a in A$ says that among the elements of $A$ there is one element that is exactly equal to $a.$



              The notation ${emptyset, {emptyset}}$ describes a set with exactly two elements.



              The first element is $emptyset.$ The second element is ${emptyset}.$
              Is one of those two elements exactly equal to ${emptyset}$?



              The notation ${ {emptyset}}$ describes a set with one element.
              That element is ${emptyset}.$



              Which element of ${ {emptyset}}$ do you think is exactly equal to $emptyset$?
              Hint: there's only one element you have to check.



              The notation ${emptyset, {emptyset, {emptyset}}}$ again describes a set with two elements.
              One element is $emptyset$ and the other is
              ${emptyset, {emptyset}}.$
              So this is definitely not the same thing as any set that has only one element.






              share|cite|improve this answer









              $endgroup$
















                6












                6








                6





                $begingroup$

                The notation $a in A$ says that among the elements of $A$ there is one element that is exactly equal to $a.$



                The notation ${emptyset, {emptyset}}$ describes a set with exactly two elements.



                The first element is $emptyset.$ The second element is ${emptyset}.$
                Is one of those two elements exactly equal to ${emptyset}$?



                The notation ${ {emptyset}}$ describes a set with one element.
                That element is ${emptyset}.$



                Which element of ${ {emptyset}}$ do you think is exactly equal to $emptyset$?
                Hint: there's only one element you have to check.



                The notation ${emptyset, {emptyset, {emptyset}}}$ again describes a set with two elements.
                One element is $emptyset$ and the other is
                ${emptyset, {emptyset}}.$
                So this is definitely not the same thing as any set that has only one element.






                share|cite|improve this answer









                $endgroup$



                The notation $a in A$ says that among the elements of $A$ there is one element that is exactly equal to $a.$



                The notation ${emptyset, {emptyset}}$ describes a set with exactly two elements.



                The first element is $emptyset.$ The second element is ${emptyset}.$
                Is one of those two elements exactly equal to ${emptyset}$?



                The notation ${ {emptyset}}$ describes a set with one element.
                That element is ${emptyset}.$



                Which element of ${ {emptyset}}$ do you think is exactly equal to $emptyset$?
                Hint: there's only one element you have to check.



                The notation ${emptyset, {emptyset, {emptyset}}}$ again describes a set with two elements.
                One element is $emptyset$ and the other is
                ${emptyset, {emptyset}}.$
                So this is definitely not the same thing as any set that has only one element.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered 1 hour ago









                David KDavid K

                53.4k341115




                53.4k341115






















                    J.S is a new contributor. Be nice, and check out our Code of Conduct.










                    draft saved

                    draft discarded


















                    J.S is a new contributor. Be nice, and check out our Code of Conduct.













                    J.S is a new contributor. Be nice, and check out our Code of Conduct.












                    J.S is a new contributor. Be nice, and check out our Code of Conduct.
















                    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%2f3081469%2fis-%25e2%2588%2585-%25e2%2588%2588-%25e2%2588%2585-true%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

                    GameSpot

                    日野市

                    Tu-95轟炸機