What would you call a finite collection of unordered objects that are not necessarily distinct?












9












$begingroup$


I Just want to know the name for this if there is one because I don't think it satisifies any of the formal definitions for sets, n-tuples, sequences, combinations, permutations, or any other enumerated objects I can think of.



For convenience, I will henceforth use the term $mathbf{ set^*}$ with an asterisk to refer to what I described in the title.



As a quick example, let $mathbf{A}$ and $mathbf{B }$ be $mathbf{ set^*}$'s where $$mathbf{A = {3,3,4,11,4,8}}$$
$$mathbf{B = {4,3,4,8,11,3}}$$



Then $mathbf{A }$ and $mathbf{ B }$ are equal.










share|cite|improve this question









$endgroup$

















    9












    $begingroup$


    I Just want to know the name for this if there is one because I don't think it satisifies any of the formal definitions for sets, n-tuples, sequences, combinations, permutations, or any other enumerated objects I can think of.



    For convenience, I will henceforth use the term $mathbf{ set^*}$ with an asterisk to refer to what I described in the title.



    As a quick example, let $mathbf{A}$ and $mathbf{B }$ be $mathbf{ set^*}$'s where $$mathbf{A = {3,3,4,11,4,8}}$$
    $$mathbf{B = {4,3,4,8,11,3}}$$



    Then $mathbf{A }$ and $mathbf{ B }$ are equal.










    share|cite|improve this question









    $endgroup$















      9












      9








      9


      2



      $begingroup$


      I Just want to know the name for this if there is one because I don't think it satisifies any of the formal definitions for sets, n-tuples, sequences, combinations, permutations, or any other enumerated objects I can think of.



      For convenience, I will henceforth use the term $mathbf{ set^*}$ with an asterisk to refer to what I described in the title.



      As a quick example, let $mathbf{A}$ and $mathbf{B }$ be $mathbf{ set^*}$'s where $$mathbf{A = {3,3,4,11,4,8}}$$
      $$mathbf{B = {4,3,4,8,11,3}}$$



      Then $mathbf{A }$ and $mathbf{ B }$ are equal.










      share|cite|improve this question









      $endgroup$




      I Just want to know the name for this if there is one because I don't think it satisifies any of the formal definitions for sets, n-tuples, sequences, combinations, permutations, or any other enumerated objects I can think of.



      For convenience, I will henceforth use the term $mathbf{ set^*}$ with an asterisk to refer to what I described in the title.



      As a quick example, let $mathbf{A}$ and $mathbf{B }$ be $mathbf{ set^*}$'s where $$mathbf{A = {3,3,4,11,4,8}}$$
      $$mathbf{B = {4,3,4,8,11,3}}$$



      Then $mathbf{A }$ and $mathbf{ B }$ are equal.







      combinatorics elementary-set-theory notation permutations definition






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Mar 25 at 11:20









      Nicholas CousarNicholas Cousar

      374312




      374312






















          4 Answers
          4






          active

          oldest

          votes


















          35












          $begingroup$

          If you're looking for something like a set which may have repeated elements, standard terms are multiset or bag. See multiset on wikipedia.






          share|cite|improve this answer









          $endgroup$





















            7












            $begingroup$

            The common term is multiset. For a formal definition, you can for instance define the set of multisets of size $n$ of a given set $A$ as $A^n/mathfrak{S}_n$ where $mathfrak{S}_n$ acts by permutation of the factors; or if you don't want to be bothered by size you can define it as a map $f: Ato mathbb{N}$ where $f(a)$ is supposed to represent the number of times $a$ appears in the multiset.



            These are two interesting models for different situations, and there are probably more.






            share|cite|improve this answer









            $endgroup$





















              4












              $begingroup$

              In this context you can identify what you call a $mathbf{ set^*}$ with a function that has a finite domain and has $mathbb N={1,2,3cdots}$ as codomain.



              $A$ and $B$ in your question can both be identified with function: $${langle3,2rangle,langle4,2rangle,langle8,1rangle,langle11,1rangle}$$Domain of the function in this case is the set ${3,4,8,11}$.






              share|cite|improve this answer









              $endgroup$





















                1












                $begingroup$

                If two objects can be distinguished by the number of times an element appears in them, that is called "multiplicity". So the more mathy version of "finite collection of unordered objects that are not necessarily distinct" would be "unordered finite collection with multiplicity" or "finite collection with multiplicity but not order".



                The single-word term for unordered collections with multiplicity is "multi-set", but I don't think there's any single-word term for finite multi-sets. Googling "math collection multiplicity no order" returns http://mathworld.wolfram.com/Set.html and https://en.wikipedia.org/wiki/Multiplicity_(mathematics) , both of which mention multisets.



                Another term that is used in the context of eigenvalues is "spectrum": the multiplicity of the eigenvalues is important, but there is no canonical order (other than the normal order of the real numbers, but that doesn't apply if they are complex). When you diagonalize or take the Jordan canonical form of a matrix, it matters how many times each eigenvalue appears, but putting the eigenvalues in a different order results in the same matrix, up to similarity.






                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%2f3161647%2fwhat-would-you-call-a-finite-collection-of-unordered-objects-that-are-not-necess%23new-answer', 'question_page');
                  }
                  );

                  Post as a guest















                  Required, but never shown

























                  4 Answers
                  4






                  active

                  oldest

                  votes








                  4 Answers
                  4






                  active

                  oldest

                  votes









                  active

                  oldest

                  votes






                  active

                  oldest

                  votes









                  35












                  $begingroup$

                  If you're looking for something like a set which may have repeated elements, standard terms are multiset or bag. See multiset on wikipedia.






                  share|cite|improve this answer









                  $endgroup$


















                    35












                    $begingroup$

                    If you're looking for something like a set which may have repeated elements, standard terms are multiset or bag. See multiset on wikipedia.






                    share|cite|improve this answer









                    $endgroup$
















                      35












                      35








                      35





                      $begingroup$

                      If you're looking for something like a set which may have repeated elements, standard terms are multiset or bag. See multiset on wikipedia.






                      share|cite|improve this answer









                      $endgroup$



                      If you're looking for something like a set which may have repeated elements, standard terms are multiset or bag. See multiset on wikipedia.







                      share|cite|improve this answer












                      share|cite|improve this answer



                      share|cite|improve this answer










                      answered Mar 25 at 11:24









                      Especially LimeEspecially Lime

                      22.8k23059




                      22.8k23059























                          7












                          $begingroup$

                          The common term is multiset. For a formal definition, you can for instance define the set of multisets of size $n$ of a given set $A$ as $A^n/mathfrak{S}_n$ where $mathfrak{S}_n$ acts by permutation of the factors; or if you don't want to be bothered by size you can define it as a map $f: Ato mathbb{N}$ where $f(a)$ is supposed to represent the number of times $a$ appears in the multiset.



                          These are two interesting models for different situations, and there are probably more.






                          share|cite|improve this answer









                          $endgroup$


















                            7












                            $begingroup$

                            The common term is multiset. For a formal definition, you can for instance define the set of multisets of size $n$ of a given set $A$ as $A^n/mathfrak{S}_n$ where $mathfrak{S}_n$ acts by permutation of the factors; or if you don't want to be bothered by size you can define it as a map $f: Ato mathbb{N}$ where $f(a)$ is supposed to represent the number of times $a$ appears in the multiset.



                            These are two interesting models for different situations, and there are probably more.






                            share|cite|improve this answer









                            $endgroup$
















                              7












                              7








                              7





                              $begingroup$

                              The common term is multiset. For a formal definition, you can for instance define the set of multisets of size $n$ of a given set $A$ as $A^n/mathfrak{S}_n$ where $mathfrak{S}_n$ acts by permutation of the factors; or if you don't want to be bothered by size you can define it as a map $f: Ato mathbb{N}$ where $f(a)$ is supposed to represent the number of times $a$ appears in the multiset.



                              These are two interesting models for different situations, and there are probably more.






                              share|cite|improve this answer









                              $endgroup$



                              The common term is multiset. For a formal definition, you can for instance define the set of multisets of size $n$ of a given set $A$ as $A^n/mathfrak{S}_n$ where $mathfrak{S}_n$ acts by permutation of the factors; or if you don't want to be bothered by size you can define it as a map $f: Ato mathbb{N}$ where $f(a)$ is supposed to represent the number of times $a$ appears in the multiset.



                              These are two interesting models for different situations, and there are probably more.







                              share|cite|improve this answer












                              share|cite|improve this answer



                              share|cite|improve this answer










                              answered Mar 25 at 11:27









                              MaxMax

                              15.9k11144




                              15.9k11144























                                  4












                                  $begingroup$

                                  In this context you can identify what you call a $mathbf{ set^*}$ with a function that has a finite domain and has $mathbb N={1,2,3cdots}$ as codomain.



                                  $A$ and $B$ in your question can both be identified with function: $${langle3,2rangle,langle4,2rangle,langle8,1rangle,langle11,1rangle}$$Domain of the function in this case is the set ${3,4,8,11}$.






                                  share|cite|improve this answer









                                  $endgroup$


















                                    4












                                    $begingroup$

                                    In this context you can identify what you call a $mathbf{ set^*}$ with a function that has a finite domain and has $mathbb N={1,2,3cdots}$ as codomain.



                                    $A$ and $B$ in your question can both be identified with function: $${langle3,2rangle,langle4,2rangle,langle8,1rangle,langle11,1rangle}$$Domain of the function in this case is the set ${3,4,8,11}$.






                                    share|cite|improve this answer









                                    $endgroup$
















                                      4












                                      4








                                      4





                                      $begingroup$

                                      In this context you can identify what you call a $mathbf{ set^*}$ with a function that has a finite domain and has $mathbb N={1,2,3cdots}$ as codomain.



                                      $A$ and $B$ in your question can both be identified with function: $${langle3,2rangle,langle4,2rangle,langle8,1rangle,langle11,1rangle}$$Domain of the function in this case is the set ${3,4,8,11}$.






                                      share|cite|improve this answer









                                      $endgroup$



                                      In this context you can identify what you call a $mathbf{ set^*}$ with a function that has a finite domain and has $mathbb N={1,2,3cdots}$ as codomain.



                                      $A$ and $B$ in your question can both be identified with function: $${langle3,2rangle,langle4,2rangle,langle8,1rangle,langle11,1rangle}$$Domain of the function in this case is the set ${3,4,8,11}$.







                                      share|cite|improve this answer












                                      share|cite|improve this answer



                                      share|cite|improve this answer










                                      answered Mar 25 at 11:33









                                      drhabdrhab

                                      104k545136




                                      104k545136























                                          1












                                          $begingroup$

                                          If two objects can be distinguished by the number of times an element appears in them, that is called "multiplicity". So the more mathy version of "finite collection of unordered objects that are not necessarily distinct" would be "unordered finite collection with multiplicity" or "finite collection with multiplicity but not order".



                                          The single-word term for unordered collections with multiplicity is "multi-set", but I don't think there's any single-word term for finite multi-sets. Googling "math collection multiplicity no order" returns http://mathworld.wolfram.com/Set.html and https://en.wikipedia.org/wiki/Multiplicity_(mathematics) , both of which mention multisets.



                                          Another term that is used in the context of eigenvalues is "spectrum": the multiplicity of the eigenvalues is important, but there is no canonical order (other than the normal order of the real numbers, but that doesn't apply if they are complex). When you diagonalize or take the Jordan canonical form of a matrix, it matters how many times each eigenvalue appears, but putting the eigenvalues in a different order results in the same matrix, up to similarity.






                                          share|cite|improve this answer









                                          $endgroup$


















                                            1












                                            $begingroup$

                                            If two objects can be distinguished by the number of times an element appears in them, that is called "multiplicity". So the more mathy version of "finite collection of unordered objects that are not necessarily distinct" would be "unordered finite collection with multiplicity" or "finite collection with multiplicity but not order".



                                            The single-word term for unordered collections with multiplicity is "multi-set", but I don't think there's any single-word term for finite multi-sets. Googling "math collection multiplicity no order" returns http://mathworld.wolfram.com/Set.html and https://en.wikipedia.org/wiki/Multiplicity_(mathematics) , both of which mention multisets.



                                            Another term that is used in the context of eigenvalues is "spectrum": the multiplicity of the eigenvalues is important, but there is no canonical order (other than the normal order of the real numbers, but that doesn't apply if they are complex). When you diagonalize or take the Jordan canonical form of a matrix, it matters how many times each eigenvalue appears, but putting the eigenvalues in a different order results in the same matrix, up to similarity.






                                            share|cite|improve this answer









                                            $endgroup$
















                                              1












                                              1








                                              1





                                              $begingroup$

                                              If two objects can be distinguished by the number of times an element appears in them, that is called "multiplicity". So the more mathy version of "finite collection of unordered objects that are not necessarily distinct" would be "unordered finite collection with multiplicity" or "finite collection with multiplicity but not order".



                                              The single-word term for unordered collections with multiplicity is "multi-set", but I don't think there's any single-word term for finite multi-sets. Googling "math collection multiplicity no order" returns http://mathworld.wolfram.com/Set.html and https://en.wikipedia.org/wiki/Multiplicity_(mathematics) , both of which mention multisets.



                                              Another term that is used in the context of eigenvalues is "spectrum": the multiplicity of the eigenvalues is important, but there is no canonical order (other than the normal order of the real numbers, but that doesn't apply if they are complex). When you diagonalize or take the Jordan canonical form of a matrix, it matters how many times each eigenvalue appears, but putting the eigenvalues in a different order results in the same matrix, up to similarity.






                                              share|cite|improve this answer









                                              $endgroup$



                                              If two objects can be distinguished by the number of times an element appears in them, that is called "multiplicity". So the more mathy version of "finite collection of unordered objects that are not necessarily distinct" would be "unordered finite collection with multiplicity" or "finite collection with multiplicity but not order".



                                              The single-word term for unordered collections with multiplicity is "multi-set", but I don't think there's any single-word term for finite multi-sets. Googling "math collection multiplicity no order" returns http://mathworld.wolfram.com/Set.html and https://en.wikipedia.org/wiki/Multiplicity_(mathematics) , both of which mention multisets.



                                              Another term that is used in the context of eigenvalues is "spectrum": the multiplicity of the eigenvalues is important, but there is no canonical order (other than the normal order of the real numbers, but that doesn't apply if they are complex). When you diagonalize or take the Jordan canonical form of a matrix, it matters how many times each eigenvalue appears, but putting the eigenvalues in a different order results in the same matrix, up to similarity.







                                              share|cite|improve this answer












                                              share|cite|improve this answer



                                              share|cite|improve this answer










                                              answered Mar 25 at 15:50









                                              AcccumulationAcccumulation

                                              7,2152619




                                              7,2152619






























                                                  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%2f3161647%2fwhat-would-you-call-a-finite-collection-of-unordered-objects-that-are-not-necess%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

                                                  How to change which sound is reproduced for terminal bell?

                                                  Can I use Tabulator js library in my java Spring + Thymeleaf project?

                                                  Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents