“a” is an element of a set of a set of “a”?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
5
down vote

favorite












I'm having a hard time conceptualizing what this means:



$a in a$



Is this saying that the a is an element of the set of set a?










share|cite|improve this question



























    up vote
    5
    down vote

    favorite












    I'm having a hard time conceptualizing what this means:



    $a in a$



    Is this saying that the a is an element of the set of set a?










    share|cite|improve this question

























      up vote
      5
      down vote

      favorite









      up vote
      5
      down vote

      favorite











      I'm having a hard time conceptualizing what this means:



      $a in a$



      Is this saying that the a is an element of the set of set a?










      share|cite|improve this question















      I'm having a hard time conceptualizing what this means:



      $a in a$



      Is this saying that the a is an element of the set of set a?







      elementary-set-theory






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited yesterday

























      asked yesterday









      edmonda7

      413




      413




















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          7
          down vote













          Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.






          share|cite|improve this answer
















          • 1




            A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
            – xbh
            yesterday










          • So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
            – edmonda7
            yesterday










          • Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
            – xbh
            yesterday






          • 2




            Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
            – Theo Bendit
            yesterday






          • 1




            @xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
            – Arthur
            yesterday











          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',
          convertImagesToLinks: true,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          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%2f2913955%2fa-is-an-element-of-a-set-of-a-set-of-a%23new-answer', 'question_page');

          );

          Post as a guest






























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          7
          down vote













          Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.






          share|cite|improve this answer
















          • 1




            A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
            – xbh
            yesterday










          • So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
            – edmonda7
            yesterday










          • Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
            – xbh
            yesterday






          • 2




            Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
            – Theo Bendit
            yesterday






          • 1




            @xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
            – Arthur
            yesterday















          up vote
          7
          down vote













          Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.






          share|cite|improve this answer
















          • 1




            A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
            – xbh
            yesterday










          • So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
            – edmonda7
            yesterday










          • Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
            – xbh
            yesterday






          • 2




            Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
            – Theo Bendit
            yesterday






          • 1




            @xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
            – Arthur
            yesterday













          up vote
          7
          down vote










          up vote
          7
          down vote









          Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.






          share|cite|improve this answer












          Yep, that's what the statement says. The statement is false, but you have interpreted it correctly.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered yesterday









          Theo Bendit

          12.9k1944




          12.9k1944







          • 1




            A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
            – xbh
            yesterday










          • So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
            – edmonda7
            yesterday










          • Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
            – xbh
            yesterday






          • 2




            Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
            – Theo Bendit
            yesterday






          • 1




            @xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
            – Arthur
            yesterday













          • 1




            A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
            – xbh
            yesterday










          • So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
            – edmonda7
            yesterday










          • Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
            – xbh
            yesterday






          • 2




            Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
            – Theo Bendit
            yesterday






          • 1




            @xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
            – Arthur
            yesterday








          1




          1




          A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
          – xbh
          yesterday




          A little flaw here: should it be "the element $a$ is an element of the set of set of $a$"?
          – xbh
          yesterday












          So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
          – edmonda7
          yesterday




          So, if i'm understanding correctly, it is false because a is defined as an element and an element cannot belong to a set that contains another set of itself?
          – edmonda7
          yesterday












          Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
          – xbh
          yesterday




          Now that I think about it, the correct statement should be the title you gave, however it does not match your post entirely.
          – xbh
          yesterday




          2




          2




          Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
          – Theo Bendit
          yesterday




          Indeed, $a = lbrace a rbrace$ violates the axiom of regularity.
          – Theo Bendit
          yesterday




          1




          1




          @xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
          – Arthur
          yesterday





          @xbh Yes, it can. Not in ZF set theory, but logically there is nothing wrong with $a=a$.
          – Arthur
          yesterday


















           

          draft saved


          draft discarded















































           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2913955%2fa-is-an-element-of-a-set-of-a-set-of-a%23new-answer', 'question_page');

          );

          Post as a guest













































































          Comments

          Popular posts from this blog

          What does second last employer means? [closed]

          List of Gilmore Girls characters

          Confectionery