Discrete Mathematics - Truth Function Problem












0














I keep trying to reason how is letter C the answer to this question, but I can't fully understand how can one find the solution to this type of problems. What I understand:




  • There's 2 arguments in the given truth function, therefore we have 2^(2) = 4 total statements. This is because we have f(x, y) = k. In the case we had 3 arguments/variables, then we would have f(x, y, z) = k.


  • The f( T, F) = T is the only statement that results true for when the values T, F are assigned to the respective variables. (i.e. In the case P = T and Q = F, or Q = T, and P = F).


  • For any compound statement the function F(T, F) has to result in true.



The algorithm for TRUE function:



Input: A truth function F with an n number of arguments x_1, x_2, x_3, ..., x_n.



Output: A statement S whose truth function is f. This statement can only involve the connectives of conjunction "AND", disjunction "OR" , and negation "~".



Step 1:



Consider a basic statement q_i for each argument x_i of f, where i = 1,2,3, .., n.



Step 2:



For each combination of values for the arguments x_1, x_2, x_3, ..., x_n. Consider the statement:



S_j = P^(1)_j "AND" P^(2)_j "AND"... "AND" P^(n)_j.



where, P^i _ j {



q_i IF x_i = T



~q_i IF x_i = F



}



Step 3:



Let J_1, J_2, J_3, ..., J_k. Be the index for the combination of values for x_1, x_2, x_3, ..., x_n that force f to produce T.



S = S_ J_1 "OR" S_ J_2 "OR" S_ J_3



CLAIM I: Every statement S_J is only true for the combination of values that we used to construct it.



CLAIM II: For each combination of values, there is only one S_J that is true for that combination.



PICTURE OF THE PROBLEM HERE:





https://imgur.com/a/jnMckeM





Sorry for the notation, I don't know any text editors for this sort of syntax. I hope is readable.



Thank you in advance!










share|cite|improve this question



























    0














    I keep trying to reason how is letter C the answer to this question, but I can't fully understand how can one find the solution to this type of problems. What I understand:




    • There's 2 arguments in the given truth function, therefore we have 2^(2) = 4 total statements. This is because we have f(x, y) = k. In the case we had 3 arguments/variables, then we would have f(x, y, z) = k.


    • The f( T, F) = T is the only statement that results true for when the values T, F are assigned to the respective variables. (i.e. In the case P = T and Q = F, or Q = T, and P = F).


    • For any compound statement the function F(T, F) has to result in true.



    The algorithm for TRUE function:



    Input: A truth function F with an n number of arguments x_1, x_2, x_3, ..., x_n.



    Output: A statement S whose truth function is f. This statement can only involve the connectives of conjunction "AND", disjunction "OR" , and negation "~".



    Step 1:



    Consider a basic statement q_i for each argument x_i of f, where i = 1,2,3, .., n.



    Step 2:



    For each combination of values for the arguments x_1, x_2, x_3, ..., x_n. Consider the statement:



    S_j = P^(1)_j "AND" P^(2)_j "AND"... "AND" P^(n)_j.



    where, P^i _ j {



    q_i IF x_i = T



    ~q_i IF x_i = F



    }



    Step 3:



    Let J_1, J_2, J_3, ..., J_k. Be the index for the combination of values for x_1, x_2, x_3, ..., x_n that force f to produce T.



    S = S_ J_1 "OR" S_ J_2 "OR" S_ J_3



    CLAIM I: Every statement S_J is only true for the combination of values that we used to construct it.



    CLAIM II: For each combination of values, there is only one S_J that is true for that combination.



    PICTURE OF THE PROBLEM HERE:





    https://imgur.com/a/jnMckeM





    Sorry for the notation, I don't know any text editors for this sort of syntax. I hope is readable.



    Thank you in advance!










    share|cite|improve this question

























      0












      0








      0







      I keep trying to reason how is letter C the answer to this question, but I can't fully understand how can one find the solution to this type of problems. What I understand:




      • There's 2 arguments in the given truth function, therefore we have 2^(2) = 4 total statements. This is because we have f(x, y) = k. In the case we had 3 arguments/variables, then we would have f(x, y, z) = k.


      • The f( T, F) = T is the only statement that results true for when the values T, F are assigned to the respective variables. (i.e. In the case P = T and Q = F, or Q = T, and P = F).


      • For any compound statement the function F(T, F) has to result in true.



      The algorithm for TRUE function:



      Input: A truth function F with an n number of arguments x_1, x_2, x_3, ..., x_n.



      Output: A statement S whose truth function is f. This statement can only involve the connectives of conjunction "AND", disjunction "OR" , and negation "~".



      Step 1:



      Consider a basic statement q_i for each argument x_i of f, where i = 1,2,3, .., n.



      Step 2:



      For each combination of values for the arguments x_1, x_2, x_3, ..., x_n. Consider the statement:



      S_j = P^(1)_j "AND" P^(2)_j "AND"... "AND" P^(n)_j.



      where, P^i _ j {



      q_i IF x_i = T



      ~q_i IF x_i = F



      }



      Step 3:



      Let J_1, J_2, J_3, ..., J_k. Be the index for the combination of values for x_1, x_2, x_3, ..., x_n that force f to produce T.



      S = S_ J_1 "OR" S_ J_2 "OR" S_ J_3



      CLAIM I: Every statement S_J is only true for the combination of values that we used to construct it.



      CLAIM II: For each combination of values, there is only one S_J that is true for that combination.



      PICTURE OF THE PROBLEM HERE:





      https://imgur.com/a/jnMckeM





      Sorry for the notation, I don't know any text editors for this sort of syntax. I hope is readable.



      Thank you in advance!










      share|cite|improve this question













      I keep trying to reason how is letter C the answer to this question, but I can't fully understand how can one find the solution to this type of problems. What I understand:




      • There's 2 arguments in the given truth function, therefore we have 2^(2) = 4 total statements. This is because we have f(x, y) = k. In the case we had 3 arguments/variables, then we would have f(x, y, z) = k.


      • The f( T, F) = T is the only statement that results true for when the values T, F are assigned to the respective variables. (i.e. In the case P = T and Q = F, or Q = T, and P = F).


      • For any compound statement the function F(T, F) has to result in true.



      The algorithm for TRUE function:



      Input: A truth function F with an n number of arguments x_1, x_2, x_3, ..., x_n.



      Output: A statement S whose truth function is f. This statement can only involve the connectives of conjunction "AND", disjunction "OR" , and negation "~".



      Step 1:



      Consider a basic statement q_i for each argument x_i of f, where i = 1,2,3, .., n.



      Step 2:



      For each combination of values for the arguments x_1, x_2, x_3, ..., x_n. Consider the statement:



      S_j = P^(1)_j "AND" P^(2)_j "AND"... "AND" P^(n)_j.



      where, P^i _ j {



      q_i IF x_i = T



      ~q_i IF x_i = F



      }



      Step 3:



      Let J_1, J_2, J_3, ..., J_k. Be the index for the combination of values for x_1, x_2, x_3, ..., x_n that force f to produce T.



      S = S_ J_1 "OR" S_ J_2 "OR" S_ J_3



      CLAIM I: Every statement S_J is only true for the combination of values that we used to construct it.



      CLAIM II: For each combination of values, there is only one S_J that is true for that combination.



      PICTURE OF THE PROBLEM HERE:





      https://imgur.com/a/jnMckeM





      Sorry for the notation, I don't know any text editors for this sort of syntax. I hope is readable.



      Thank you in advance!







      discrete-mathematics logic propositional-calculus






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 19 '18 at 0:40









      ChalupaBatmac

      1




      1






















          1 Answer
          1






          active

          oldest

          votes


















          0














          The problem uses $f(p,q)$, so $p$ is the first argument, and $q$ the second. So, the truth table shows that the only case where $f$ returns True is if $p=T$ and $q=F$. If $q=T$ and $p=F$ then $f(p,q)=F$. So, what you have at the very end of the second bullet point is wrong. (And maybe now it is easier to see what the correct answer is!)






          share|cite|improve this answer





















          • Do we assume p corresponds to the first argument, x_1, or is this based on the results of the truth table formed?
            – ChalupaBatmac
            Nov 19 '18 at 16:25












          • @ChalupaBatmac Yes, it is assumed that $p$ refers to the first argument, and $q$ to the second.
            – Bram28
            Nov 19 '18 at 16:27










          • Ok, so then it comes down to verifying the truth values of each compound statement using the values given by the function f. Thank you for the quick response.
            – ChalupaBatmac
            Nov 19 '18 at 16:29










          • @ChalupaBatmac Yes ... should be easy. Glad I could help!
            – Bram28
            Nov 19 '18 at 17:06











          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%2f3004342%2fdiscrete-mathematics-truth-function-problem%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









          0














          The problem uses $f(p,q)$, so $p$ is the first argument, and $q$ the second. So, the truth table shows that the only case where $f$ returns True is if $p=T$ and $q=F$. If $q=T$ and $p=F$ then $f(p,q)=F$. So, what you have at the very end of the second bullet point is wrong. (And maybe now it is easier to see what the correct answer is!)






          share|cite|improve this answer





















          • Do we assume p corresponds to the first argument, x_1, or is this based on the results of the truth table formed?
            – ChalupaBatmac
            Nov 19 '18 at 16:25












          • @ChalupaBatmac Yes, it is assumed that $p$ refers to the first argument, and $q$ to the second.
            – Bram28
            Nov 19 '18 at 16:27










          • Ok, so then it comes down to verifying the truth values of each compound statement using the values given by the function f. Thank you for the quick response.
            – ChalupaBatmac
            Nov 19 '18 at 16:29










          • @ChalupaBatmac Yes ... should be easy. Glad I could help!
            – Bram28
            Nov 19 '18 at 17:06
















          0














          The problem uses $f(p,q)$, so $p$ is the first argument, and $q$ the second. So, the truth table shows that the only case where $f$ returns True is if $p=T$ and $q=F$. If $q=T$ and $p=F$ then $f(p,q)=F$. So, what you have at the very end of the second bullet point is wrong. (And maybe now it is easier to see what the correct answer is!)






          share|cite|improve this answer





















          • Do we assume p corresponds to the first argument, x_1, or is this based on the results of the truth table formed?
            – ChalupaBatmac
            Nov 19 '18 at 16:25












          • @ChalupaBatmac Yes, it is assumed that $p$ refers to the first argument, and $q$ to the second.
            – Bram28
            Nov 19 '18 at 16:27










          • Ok, so then it comes down to verifying the truth values of each compound statement using the values given by the function f. Thank you for the quick response.
            – ChalupaBatmac
            Nov 19 '18 at 16:29










          • @ChalupaBatmac Yes ... should be easy. Glad I could help!
            – Bram28
            Nov 19 '18 at 17:06














          0












          0








          0






          The problem uses $f(p,q)$, so $p$ is the first argument, and $q$ the second. So, the truth table shows that the only case where $f$ returns True is if $p=T$ and $q=F$. If $q=T$ and $p=F$ then $f(p,q)=F$. So, what you have at the very end of the second bullet point is wrong. (And maybe now it is easier to see what the correct answer is!)






          share|cite|improve this answer












          The problem uses $f(p,q)$, so $p$ is the first argument, and $q$ the second. So, the truth table shows that the only case where $f$ returns True is if $p=T$ and $q=F$. If $q=T$ and $p=F$ then $f(p,q)=F$. So, what you have at the very end of the second bullet point is wrong. (And maybe now it is easier to see what the correct answer is!)







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Nov 19 '18 at 1:37









          Bram28

          60.2k44590




          60.2k44590












          • Do we assume p corresponds to the first argument, x_1, or is this based on the results of the truth table formed?
            – ChalupaBatmac
            Nov 19 '18 at 16:25












          • @ChalupaBatmac Yes, it is assumed that $p$ refers to the first argument, and $q$ to the second.
            – Bram28
            Nov 19 '18 at 16:27










          • Ok, so then it comes down to verifying the truth values of each compound statement using the values given by the function f. Thank you for the quick response.
            – ChalupaBatmac
            Nov 19 '18 at 16:29










          • @ChalupaBatmac Yes ... should be easy. Glad I could help!
            – Bram28
            Nov 19 '18 at 17:06


















          • Do we assume p corresponds to the first argument, x_1, or is this based on the results of the truth table formed?
            – ChalupaBatmac
            Nov 19 '18 at 16:25












          • @ChalupaBatmac Yes, it is assumed that $p$ refers to the first argument, and $q$ to the second.
            – Bram28
            Nov 19 '18 at 16:27










          • Ok, so then it comes down to verifying the truth values of each compound statement using the values given by the function f. Thank you for the quick response.
            – ChalupaBatmac
            Nov 19 '18 at 16:29










          • @ChalupaBatmac Yes ... should be easy. Glad I could help!
            – Bram28
            Nov 19 '18 at 17:06
















          Do we assume p corresponds to the first argument, x_1, or is this based on the results of the truth table formed?
          – ChalupaBatmac
          Nov 19 '18 at 16:25






          Do we assume p corresponds to the first argument, x_1, or is this based on the results of the truth table formed?
          – ChalupaBatmac
          Nov 19 '18 at 16:25














          @ChalupaBatmac Yes, it is assumed that $p$ refers to the first argument, and $q$ to the second.
          – Bram28
          Nov 19 '18 at 16:27




          @ChalupaBatmac Yes, it is assumed that $p$ refers to the first argument, and $q$ to the second.
          – Bram28
          Nov 19 '18 at 16:27












          Ok, so then it comes down to verifying the truth values of each compound statement using the values given by the function f. Thank you for the quick response.
          – ChalupaBatmac
          Nov 19 '18 at 16:29




          Ok, so then it comes down to verifying the truth values of each compound statement using the values given by the function f. Thank you for the quick response.
          – ChalupaBatmac
          Nov 19 '18 at 16:29












          @ChalupaBatmac Yes ... should be easy. Glad I could help!
          – Bram28
          Nov 19 '18 at 17:06




          @ChalupaBatmac Yes ... should be easy. Glad I could help!
          – Bram28
          Nov 19 '18 at 17:06


















          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.





          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%2fmath.stackexchange.com%2fquestions%2f3004342%2fdiscrete-mathematics-truth-function-problem%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