Order Topology on a Preorder












0












$begingroup$


While looking at the definition of the order topology defined on a total order (https://en.wikipedia.org/wiki/Order_topology), I realized I needed a generalization to preorders. So ultimately the question: Is there a generalization of the order topology to preorders. If so, what is it? If not, what are some workarounds?



Some motivation:
My idea is to use “dense” preorders to model cause and effect where a<=b iff a causes b. The topology would make it possible to capture the idea that it is posible certian events are “closer” to directly causing another event.










share|cite|improve this question









$endgroup$

















    0












    $begingroup$


    While looking at the definition of the order topology defined on a total order (https://en.wikipedia.org/wiki/Order_topology), I realized I needed a generalization to preorders. So ultimately the question: Is there a generalization of the order topology to preorders. If so, what is it? If not, what are some workarounds?



    Some motivation:
    My idea is to use “dense” preorders to model cause and effect where a<=b iff a causes b. The topology would make it possible to capture the idea that it is posible certian events are “closer” to directly causing another event.










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      While looking at the definition of the order topology defined on a total order (https://en.wikipedia.org/wiki/Order_topology), I realized I needed a generalization to preorders. So ultimately the question: Is there a generalization of the order topology to preorders. If so, what is it? If not, what are some workarounds?



      Some motivation:
      My idea is to use “dense” preorders to model cause and effect where a<=b iff a causes b. The topology would make it possible to capture the idea that it is posible certian events are “closer” to directly causing another event.










      share|cite|improve this question









      $endgroup$




      While looking at the definition of the order topology defined on a total order (https://en.wikipedia.org/wiki/Order_topology), I realized I needed a generalization to preorders. So ultimately the question: Is there a generalization of the order topology to preorders. If so, what is it? If not, what are some workarounds?



      Some motivation:
      My idea is to use “dense” preorders to model cause and effect where a<=b iff a causes b. The topology would make it possible to capture the idea that it is posible certian events are “closer” to directly causing another event.







      general-topology relations order-theory order-topology






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Jan 17 at 14:46









      user512716user512716

      816




      816






















          2 Answers
          2






          active

          oldest

          votes


















          1












          $begingroup$

          Define for each $x in X$, the lower and upper sets $L(x) = {y in X: y < x}$ and $U(x) = {y in X: y > x}$. By definition all such sets together form a subbase for the order topology when $(X,<)$ is a linear order.



          So if you want to generalise to a partial order $(X,le)$, just define $x < y$ as $ x le y$ and $x neq y$ and use the same subbase.






          share|cite|improve this answer









          $endgroup$





















            0












            $begingroup$

            There is the Alexandrov topology on a pre-ordered set.

            It is not a generalization of the order topology you link to, but it might be what you're looking for






            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%2f3077067%2forder-topology-on-a-preorder%23new-answer', 'question_page');
              }
              );

              Post as a guest















              Required, but never shown

























              2 Answers
              2






              active

              oldest

              votes








              2 Answers
              2






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes









              1












              $begingroup$

              Define for each $x in X$, the lower and upper sets $L(x) = {y in X: y < x}$ and $U(x) = {y in X: y > x}$. By definition all such sets together form a subbase for the order topology when $(X,<)$ is a linear order.



              So if you want to generalise to a partial order $(X,le)$, just define $x < y$ as $ x le y$ and $x neq y$ and use the same subbase.






              share|cite|improve this answer









              $endgroup$


















                1












                $begingroup$

                Define for each $x in X$, the lower and upper sets $L(x) = {y in X: y < x}$ and $U(x) = {y in X: y > x}$. By definition all such sets together form a subbase for the order topology when $(X,<)$ is a linear order.



                So if you want to generalise to a partial order $(X,le)$, just define $x < y$ as $ x le y$ and $x neq y$ and use the same subbase.






                share|cite|improve this answer









                $endgroup$
















                  1












                  1








                  1





                  $begingroup$

                  Define for each $x in X$, the lower and upper sets $L(x) = {y in X: y < x}$ and $U(x) = {y in X: y > x}$. By definition all such sets together form a subbase for the order topology when $(X,<)$ is a linear order.



                  So if you want to generalise to a partial order $(X,le)$, just define $x < y$ as $ x le y$ and $x neq y$ and use the same subbase.






                  share|cite|improve this answer









                  $endgroup$



                  Define for each $x in X$, the lower and upper sets $L(x) = {y in X: y < x}$ and $U(x) = {y in X: y > x}$. By definition all such sets together form a subbase for the order topology when $(X,<)$ is a linear order.



                  So if you want to generalise to a partial order $(X,le)$, just define $x < y$ as $ x le y$ and $x neq y$ and use the same subbase.







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Jan 17 at 18:52









                  Henno BrandsmaHenno Brandsma

                  111k348118




                  111k348118























                      0












                      $begingroup$

                      There is the Alexandrov topology on a pre-ordered set.

                      It is not a generalization of the order topology you link to, but it might be what you're looking for






                      share|cite|improve this answer









                      $endgroup$


















                        0












                        $begingroup$

                        There is the Alexandrov topology on a pre-ordered set.

                        It is not a generalization of the order topology you link to, but it might be what you're looking for






                        share|cite|improve this answer









                        $endgroup$
















                          0












                          0








                          0





                          $begingroup$

                          There is the Alexandrov topology on a pre-ordered set.

                          It is not a generalization of the order topology you link to, but it might be what you're looking for






                          share|cite|improve this answer









                          $endgroup$



                          There is the Alexandrov topology on a pre-ordered set.

                          It is not a generalization of the order topology you link to, but it might be what you're looking for







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered Jan 17 at 15:28









                          amrsaamrsa

                          3,6702618




                          3,6702618






























                              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%2f3077067%2forder-topology-on-a-preorder%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

                              Can a sorcerer learn a 5th-level spell early by creating spell slots using the Font of Magic feature?

                              Does disintegrating a polymorphed enemy still kill it after the 2018 errata?

                              A Topological Invariant for $pi_3(U(n))$