Exercise 26 . (For-Credit: 6 points) (partially adopted from textbook exercise 3-8) Determine whether the following argument is valid or not by...

Exercise 26 ... (For-Credit: 6 points)

   (partially adopted from textbook exercise 3-8)

   Determine whether the following argument is valid or not

   by showing how truth tables are utilized and interpreted:

   [26-1]   P1:  P -> Q

             P2:  Q -> R

             P3: ~R

           ----------------

              C: ~P

   [26-2]   P1: ~D V ~F

             P2:  G -> (D & F)

            -------------------

              C: ~G

Exercise 27 ... (For-Credit: 6 points)

   Do the three things with the argument given below:

   1. (a) Identify atomic sentences employed in the argument; and

      (b) assign the sentence constants (P, Q, R) to those atomic

          sentences (in their order of appearance in the argument).

   2. Symbolize the whole argument by employing those sentence

      constants and the proper connectives.

   3. Determine whether the following argument is valid or not by

      demonstrating how Truth Tables can be employed and interpreted:

      P1: If things are caused to exist,

           then the infinite regress of existence is not possible.

      P2: God is not the ultimate cause of existence,

           'only if' the infinite regress of existence is possible.

      P3: By the way, things are caused to exist.

       C: Therefore, God is the ultimate cause of existence.