Is it sufficient to prove $P(x) geq a$ if we already know $P(x) > a$?












0












$begingroup$


Is it sufficient to prove $P(x) ge (text{or} le) a$ if we already know $P(x) > (text{or} <)a$?



For example, to prove
$$
forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} le 2
$$



Suppose I have already proved
$$
forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} < frac{7}{4} - frac{1}{n}
$$

Then, are we done? (Because $frac{7}{4}-frac{1}{n} < 2 le 2$)










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    Is it sufficient to prove $P(x) ge (text{or} le) a$ if we already know $P(x) > (text{or} <)a$?



    For example, to prove
    $$
    forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} le 2
    $$



    Suppose I have already proved
    $$
    forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} < frac{7}{4} - frac{1}{n}
    $$

    Then, are we done? (Because $frac{7}{4}-frac{1}{n} < 2 le 2$)










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Is it sufficient to prove $P(x) ge (text{or} le) a$ if we already know $P(x) > (text{or} <)a$?



      For example, to prove
      $$
      forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} le 2
      $$



      Suppose I have already proved
      $$
      forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} < frac{7}{4} - frac{1}{n}
      $$

      Then, are we done? (Because $frac{7}{4}-frac{1}{n} < 2 le 2$)










      share|cite|improve this question











      $endgroup$




      Is it sufficient to prove $P(x) ge (text{or} le) a$ if we already know $P(x) > (text{or} <)a$?



      For example, to prove
      $$
      forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} le 2
      $$



      Suppose I have already proved
      $$
      forall n ge 1 , sum_{i=1}^{n}frac{1}{i^2} < frac{7}{4} - frac{1}{n}
      $$

      Then, are we done? (Because $frac{7}{4}-frac{1}{n} < 2 le 2$)







      discrete-mathematics theorem-provers






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 12 at 9:10









      rtybase

      11.6k31534




      11.6k31534










      asked Jan 12 at 6:26









      王文军 or Wenjun Wang王文军 or Wenjun Wang

      496




      496






















          1 Answer
          1






          active

          oldest

          votes


















          1












          $begingroup$

          Of course. If "greater than" is true, then "greater than or equal to" is true. Look at the truth table under OR here: https://medium.com/i-math/intro-to-truth-tables-boolean-algebra-73b331dd9b94.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Opps! I just found that $le$ means less that or equal to in English, so it is actually kind of a logic union.
            $endgroup$
            – 王文军 or Wenjun Wang
            Jan 12 at 6:53












          Your Answer








          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%2f3070645%2fis-it-sufficient-to-prove-px-geq-a-if-we-already-know-px-a%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









          1












          $begingroup$

          Of course. If "greater than" is true, then "greater than or equal to" is true. Look at the truth table under OR here: https://medium.com/i-math/intro-to-truth-tables-boolean-algebra-73b331dd9b94.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Opps! I just found that $le$ means less that or equal to in English, so it is actually kind of a logic union.
            $endgroup$
            – 王文军 or Wenjun Wang
            Jan 12 at 6:53
















          1












          $begingroup$

          Of course. If "greater than" is true, then "greater than or equal to" is true. Look at the truth table under OR here: https://medium.com/i-math/intro-to-truth-tables-boolean-algebra-73b331dd9b94.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Opps! I just found that $le$ means less that or equal to in English, so it is actually kind of a logic union.
            $endgroup$
            – 王文军 or Wenjun Wang
            Jan 12 at 6:53














          1












          1








          1





          $begingroup$

          Of course. If "greater than" is true, then "greater than or equal to" is true. Look at the truth table under OR here: https://medium.com/i-math/intro-to-truth-tables-boolean-algebra-73b331dd9b94.






          share|cite|improve this answer









          $endgroup$



          Of course. If "greater than" is true, then "greater than or equal to" is true. Look at the truth table under OR here: https://medium.com/i-math/intro-to-truth-tables-boolean-algebra-73b331dd9b94.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Jan 12 at 6:48









          PiKindOfGuyPiKindOfGuy

          18611




          18611












          • $begingroup$
            Opps! I just found that $le$ means less that or equal to in English, so it is actually kind of a logic union.
            $endgroup$
            – 王文军 or Wenjun Wang
            Jan 12 at 6:53


















          • $begingroup$
            Opps! I just found that $le$ means less that or equal to in English, so it is actually kind of a logic union.
            $endgroup$
            – 王文军 or Wenjun Wang
            Jan 12 at 6:53
















          $begingroup$
          Opps! I just found that $le$ means less that or equal to in English, so it is actually kind of a logic union.
          $endgroup$
          – 王文军 or Wenjun Wang
          Jan 12 at 6:53




          $begingroup$
          Opps! I just found that $le$ means less that or equal to in English, so it is actually kind of a logic union.
          $endgroup$
          – 王文军 or Wenjun Wang
          Jan 12 at 6:53


















          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%2f3070645%2fis-it-sufficient-to-prove-px-geq-a-if-we-already-know-px-a%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

          Bressuire

          Cabo Verde

          Gyllenstierna