Page 175 - Math Course 2 (Book 2)
P. 175

Truth Tables and Logic




               Construct Truth Tables
                                                                  Construct a truth table for p v (~q ⋀ r).
                   Example                                        Step 1

                                                                  Make columns with the headings p, q, r, ~q, ~q ⋀ r,
                                                                  and p ⋁ (~q ⋀ r).
                Construct a truth table for ~p ⋁ q.

                Step 1                                                p    q     r   ~q   ~q ⋀ r  p ⋁ (~q ⋀ r)
                Make columns with the heading p, q, ~p, and ~p v q.

                        p       q       ~p       ~p ⋁ q













                Step 2
                List the possible combinations of truth values for p
                and q.                                            Step 2

                        p       q       ~p       ~p ⋁ q           List the possible combinations of truth values for p,
                                                                  q, and r.
                        T       T                                     p    q     r   ~q   ~q ⋀ r  p ⋁ (~q ⋀ r)
                        T       F                                     T    T    T
                                                                      T    F    T
                        F       T
                                                                      T    T    F
                        F       F                                     T    F    F

                Step 3                                                F    T    T
                Use the truth values of p to determine the truth      F    F    T
                values of ~p.
                                                                      F    T    F
                        p       q       ~p       ~p ⋁ q               F    F    F


                        T       T       F
                        T       F       F                         Step 3
                                                                  Use the truth values of q to determine the truth
                        F       T       T
                                                                  values of ~q.
                        F       F       T
                                                                      p    q     r   ~q   ~q ⋀ r  p ⋁ (~q ⋀ r)
                Step 4                                                T    T    T    F
                Use the truth values of ~p and q to write the truth
                values for ~p v q.                                    T    F    T    T
                                    Answer                            T    T    F    F
                         p      q      ~p      ~p ⋁ q                 T    F    F    T
                                                                      F    T    T    F
                         T      T      F         T
                                                                      F    F    T    T
                         T      F      F         F
                                                                      F    T    F    F
                         F      T      T         T
                                                                      F    F    F    T
                         F      F      T         T

                                                                                                                 167
   170   171   172   173   174   175   176   177   178   179   180