Consider the following sentences: (a) (if P then Q) or (if Q then P) (b) (not Q) or not [if P then (not Q) and P] (c) (if P then (not Q)) not (P and Q) (d) [if (P or Q) then R] [if P then R and if Q and R] (e) [if P then (Q and R)] [if P then Q or if P then R] (f) [if P then (if Q then R)] if (P and Q) then R] (g) [if P then (Q or R)] [if (P and (not Q)) then R] (h) [P and if Q then R] [if ((not P) or Q) then (P and R)]