Does Max Planar 3-SAT admit a PTAS?











up vote
6
down vote

favorite












Suppose we are given a formula $phi$ of 3-SAT, with variables $x_1,dots, x_n$ and clauses $C_1,dots, C_m$. Consider the graph $G_phi$ where there is one node for each clause $C_i$, for each positive literal $x_i$ and for each negative literal $overline{x_i}$. A literal is adjacent to a clause if and only if this clause contains the literal. $phi$ is a planar instance If $G_phi$ is planar.



Max planar 3-SAT is defined as the restriction of Max 3-SAT to planar instances.



This problem is known to be NP-hard. Is this problem also APX-Hard or there exists a known PTAS for this problem ?










share|cite|improve this question


























    up vote
    6
    down vote

    favorite












    Suppose we are given a formula $phi$ of 3-SAT, with variables $x_1,dots, x_n$ and clauses $C_1,dots, C_m$. Consider the graph $G_phi$ where there is one node for each clause $C_i$, for each positive literal $x_i$ and for each negative literal $overline{x_i}$. A literal is adjacent to a clause if and only if this clause contains the literal. $phi$ is a planar instance If $G_phi$ is planar.



    Max planar 3-SAT is defined as the restriction of Max 3-SAT to planar instances.



    This problem is known to be NP-hard. Is this problem also APX-Hard or there exists a known PTAS for this problem ?










    share|cite|improve this question
























      up vote
      6
      down vote

      favorite









      up vote
      6
      down vote

      favorite











      Suppose we are given a formula $phi$ of 3-SAT, with variables $x_1,dots, x_n$ and clauses $C_1,dots, C_m$. Consider the graph $G_phi$ where there is one node for each clause $C_i$, for each positive literal $x_i$ and for each negative literal $overline{x_i}$. A literal is adjacent to a clause if and only if this clause contains the literal. $phi$ is a planar instance If $G_phi$ is planar.



      Max planar 3-SAT is defined as the restriction of Max 3-SAT to planar instances.



      This problem is known to be NP-hard. Is this problem also APX-Hard or there exists a known PTAS for this problem ?










      share|cite|improve this question













      Suppose we are given a formula $phi$ of 3-SAT, with variables $x_1,dots, x_n$ and clauses $C_1,dots, C_m$. Consider the graph $G_phi$ where there is one node for each clause $C_i$, for each positive literal $x_i$ and for each negative literal $overline{x_i}$. A literal is adjacent to a clause if and only if this clause contains the literal. $phi$ is a planar instance If $G_phi$ is planar.



      Max planar 3-SAT is defined as the restriction of Max 3-SAT to planar instances.



      This problem is known to be NP-hard. Is this problem also APX-Hard or there exists a known PTAS for this problem ?







      reference-request complexity-classes approximation-algorithms approximation-hardness planar-graphs






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 20 at 14:12









      Mathieu Mari

      332




      332






















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          10
          down vote



          accepted










          Yes, a PTAS for Max-Planar-3-SAT can be constructed by using Brenda Baker's approach.

          This has been observed, for instance, in Theorem 17 in




          Pierluigi Crescenzi and LucaTrevisan:

          "Max NP-completeness made easy"

          Theoretical Computer Science 28, (1999), Pages 65-79







          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: "114"
            };
            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: false,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: null,
            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%2fcstheory.stackexchange.com%2fquestions%2f41913%2fdoes-max-planar-3-sat-admit-a-ptas%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








            up vote
            10
            down vote



            accepted










            Yes, a PTAS for Max-Planar-3-SAT can be constructed by using Brenda Baker's approach.

            This has been observed, for instance, in Theorem 17 in




            Pierluigi Crescenzi and LucaTrevisan:

            "Max NP-completeness made easy"

            Theoretical Computer Science 28, (1999), Pages 65-79







            share|cite|improve this answer

























              up vote
              10
              down vote



              accepted










              Yes, a PTAS for Max-Planar-3-SAT can be constructed by using Brenda Baker's approach.

              This has been observed, for instance, in Theorem 17 in




              Pierluigi Crescenzi and LucaTrevisan:

              "Max NP-completeness made easy"

              Theoretical Computer Science 28, (1999), Pages 65-79







              share|cite|improve this answer























                up vote
                10
                down vote



                accepted







                up vote
                10
                down vote



                accepted






                Yes, a PTAS for Max-Planar-3-SAT can be constructed by using Brenda Baker's approach.

                This has been observed, for instance, in Theorem 17 in




                Pierluigi Crescenzi and LucaTrevisan:

                "Max NP-completeness made easy"

                Theoretical Computer Science 28, (1999), Pages 65-79







                share|cite|improve this answer












                Yes, a PTAS for Max-Planar-3-SAT can be constructed by using Brenda Baker's approach.

                This has been observed, for instance, in Theorem 17 in




                Pierluigi Crescenzi and LucaTrevisan:

                "Max NP-completeness made easy"

                Theoretical Computer Science 28, (1999), Pages 65-79








                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Nov 20 at 15:14









                Gamow

                3,66931331




                3,66931331






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Theoretical Computer Science 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.





                    Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                    Please pay close attention to the following guidance:


                    • 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.


                    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%2fcstheory.stackexchange.com%2fquestions%2f41913%2fdoes-max-planar-3-sat-admit-a-ptas%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

                    AnyDesk - Fatal Program Failure

                    How to calibrate 16:9 built-in touch-screen to a 4:3 resolution?

                    QoS: MAC-Priority for clients behind a repeater