I.   Using the method described in this lesson, write derivations
            for the following problems:

           A.   Derive ~(P & ~P) from scratch

           B.   Derive P from

               1.   P v (Q v R)                 Premise
               2.   Q -> P                      Premise
               3.   ~R                          Premise

      II.   As preludes to the next lesson, write derivations for the
            following problems:

           A.   Derive Q from

               1.   P & ~P                      Premise

           B.   Derive ~P <-> (P -> ~P) from scratch