Due Wednesday February 5 in the Assignment Box on NRoss 5th floor by 5:00.

From our text SYMLOG

• Page 199: Exercise 5.3.3 (b), (d).
• Page 204: Exercise 5.4.1 (b). Give reasons for your answer (either a counterexample if it is false, or an informal argument if it is true).
• Page 204: Exercise 5.4.4 (f). Give a SYMLOG printout deriving both \alpha and ¬\alpha for some wff \alpha. [This is the formal way to demonstrate the set is SD-inconsistent.]
• Page 204: Exercise 5.4.5 (d). Give a SYMLOG printout.
• Page 204: Exercise 5.4.6 (b), (j). Give a SYMLOG printout.
• Page 204: Exercise 5.4.7 (h).
• Give two demonstrations that the following arguments are valid:
(a)       A -> B                (b)  ¬ A v B          (c)
___________                 __________            ________
¬ B -> ¬ A                      A -> B               A v ¬A


(i) give an SD derivation in symlog
(ii) give an informal argument refering to the truth of the presmise and the conclusion.
[Hint: there should be some similarity between these two arguments. If you can find one, you could try translating to get the essence of a proof of the other type. Of course, there are many different derivations for any valid argument. Some are longer or uglier or harder to figure out.]