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












0












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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 $frac{7}{4}-frac{1}{n} < 2 le 2$)










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    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






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      edited Jan 12 at 9:10









      rtybase

      11.4k31533




      11.4k31533










      asked Jan 12 at 6:26









      ShinobuIsMyWifeShinobuIsMyWife

      463




      463






















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          $begingroup$

          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









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











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          $begingroup$

          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.
            $endgroup$
            – ShinobuIsMyWife
            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.
            $endgroup$
            – ShinobuIsMyWife
            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.
            $endgroup$
            – ShinobuIsMyWife
            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.
            $endgroup$
            – ShinobuIsMyWife
            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.
          $endgroup$
          – ShinobuIsMyWife
          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.
          $endgroup$
          – ShinobuIsMyWife
          Jan 12 at 6:53


















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