Property of set exclusion set.

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











up vote
7
down vote

favorite
1












Let $T$ have the property that for all sets $A, B in T$ we have that $(Abackslash B) in T$.



How can I prove that $forall A,B in T, Acap B in T$?



I was thinking I should start with both expressions:
$(Abackslash B) in T$.



$(Bbackslash A) in T$.



and show that$ (A cup B)backslash((Abackslash B)cup (B backslash A)=Acap B in T$.



I'm not sure how to show that the final part is in that set. It doesn't say anything about unions.










share|cite|improve this question



























    up vote
    7
    down vote

    favorite
    1












    Let $T$ have the property that for all sets $A, B in T$ we have that $(Abackslash B) in T$.



    How can I prove that $forall A,B in T, Acap B in T$?



    I was thinking I should start with both expressions:
    $(Abackslash B) in T$.



    $(Bbackslash A) in T$.



    and show that$ (A cup B)backslash((Abackslash B)cup (B backslash A)=Acap B in T$.



    I'm not sure how to show that the final part is in that set. It doesn't say anything about unions.










    share|cite|improve this question

























      up vote
      7
      down vote

      favorite
      1









      up vote
      7
      down vote

      favorite
      1






      1





      Let $T$ have the property that for all sets $A, B in T$ we have that $(Abackslash B) in T$.



      How can I prove that $forall A,B in T, Acap B in T$?



      I was thinking I should start with both expressions:
      $(Abackslash B) in T$.



      $(Bbackslash A) in T$.



      and show that$ (A cup B)backslash((Abackslash B)cup (B backslash A)=Acap B in T$.



      I'm not sure how to show that the final part is in that set. It doesn't say anything about unions.










      share|cite|improve this question















      Let $T$ have the property that for all sets $A, B in T$ we have that $(Abackslash B) in T$.



      How can I prove that $forall A,B in T, Acap B in T$?



      I was thinking I should start with both expressions:
      $(Abackslash B) in T$.



      $(Bbackslash A) in T$.



      and show that$ (A cup B)backslash((Abackslash B)cup (B backslash A)=Acap B in T$.



      I'm not sure how to show that the final part is in that set. It doesn't say anything about unions.







      elementary-set-theory






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Sep 5 at 18:53









      Asaf Karagila♦

      295k32411739




      295k32411739










      asked Sep 5 at 18:43









      WesleyGroupshaveFeelingsToo

      340113




      340113




















          2 Answers
          2






          active

          oldest

          votes

















          up vote
          11
          down vote



          accepted










          Hint: $Acap B=Asetminus (Asetminus B)$






          share|cite|improve this answer
















          • 1




            Hold that thought.
            – WesleyGroupshaveFeelingsToo
            Sep 5 at 18:48






          • 2




            Beat me to it! +1
            – Fimpellizieri
            Sep 5 at 18:48










          • I just had to show that these two were equivalent and that did the trick, thanks guys.
            – WesleyGroupshaveFeelingsToo
            Sep 5 at 19:34


















          up vote
          8
          down vote













          Write $Acap B = Asetminus(Asetminus B)$.






          share|cite|improve this answer




















            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%2f2906643%2fproperty-of-set-exclusion-set%23new-answer', 'question_page');

            );

            Post as a guest






























            2 Answers
            2






            active

            oldest

            votes








            2 Answers
            2






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            11
            down vote



            accepted










            Hint: $Acap B=Asetminus (Asetminus B)$






            share|cite|improve this answer
















            • 1




              Hold that thought.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 18:48






            • 2




              Beat me to it! +1
              – Fimpellizieri
              Sep 5 at 18:48










            • I just had to show that these two were equivalent and that did the trick, thanks guys.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 19:34















            up vote
            11
            down vote



            accepted










            Hint: $Acap B=Asetminus (Asetminus B)$






            share|cite|improve this answer
















            • 1




              Hold that thought.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 18:48






            • 2




              Beat me to it! +1
              – Fimpellizieri
              Sep 5 at 18:48










            • I just had to show that these two were equivalent and that did the trick, thanks guys.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 19:34













            up vote
            11
            down vote



            accepted







            up vote
            11
            down vote



            accepted






            Hint: $Acap B=Asetminus (Asetminus B)$






            share|cite|improve this answer












            Hint: $Acap B=Asetminus (Asetminus B)$







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Sep 5 at 18:47









            b00n heT

            8,95511833




            8,95511833







            • 1




              Hold that thought.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 18:48






            • 2




              Beat me to it! +1
              – Fimpellizieri
              Sep 5 at 18:48










            • I just had to show that these two were equivalent and that did the trick, thanks guys.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 19:34













            • 1




              Hold that thought.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 18:48






            • 2




              Beat me to it! +1
              – Fimpellizieri
              Sep 5 at 18:48










            • I just had to show that these two were equivalent and that did the trick, thanks guys.
              – WesleyGroupshaveFeelingsToo
              Sep 5 at 19:34








            1




            1




            Hold that thought.
            – WesleyGroupshaveFeelingsToo
            Sep 5 at 18:48




            Hold that thought.
            – WesleyGroupshaveFeelingsToo
            Sep 5 at 18:48




            2




            2




            Beat me to it! +1
            – Fimpellizieri
            Sep 5 at 18:48




            Beat me to it! +1
            – Fimpellizieri
            Sep 5 at 18:48












            I just had to show that these two were equivalent and that did the trick, thanks guys.
            – WesleyGroupshaveFeelingsToo
            Sep 5 at 19:34





            I just had to show that these two were equivalent and that did the trick, thanks guys.
            – WesleyGroupshaveFeelingsToo
            Sep 5 at 19:34











            up vote
            8
            down vote













            Write $Acap B = Asetminus(Asetminus B)$.






            share|cite|improve this answer
























              up vote
              8
              down vote













              Write $Acap B = Asetminus(Asetminus B)$.






              share|cite|improve this answer






















                up vote
                8
                down vote










                up vote
                8
                down vote









                Write $Acap B = Asetminus(Asetminus B)$.






                share|cite|improve this answer












                Write $Acap B = Asetminus(Asetminus B)$.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Sep 5 at 18:48









                Fimpellizieri

                16.9k11836




                16.9k11836



























                     

                    draft saved


                    draft discarded















































                     


                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function ()
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2906643%2fproperty-of-set-exclusion-set%23new-answer', 'question_page');

                    );

                    Post as a guest













































































                    Popular posts from this blog

                    How to check contact read email or not when send email to Individual?

                    Displaying single band from multi-band raster using QGIS

                    How many registers does an x86_64 CPU actually have?