1. Construct a regular proof to derive the conclusion of the following argument:
1. H v (~T > R)
2. Hv (E > F)
3. ~T v E
4. ~H & D
/ R v F
2. Construct a regular proof to derive the conclusion of the following argument:
1. N > R
2. O <> R
3. (O > R) > L
/ (N > O) & L
3. Construct a regular proof to derive the conclusion of the following argument:
1. C
2. (C & T) > ~T
3. (C & ~T) > T
/ T <> ~T
4. Construct a regular proof to derive the conclusion of the following argument:
1. X >Y
2. (Y v ~X) > (Y > Z)
/ ~Z > ~X
5. Construct a regular proof to derive the conclusion of the following argument:
1. (A & U) <> ~R
2. ~(~R v ~A)
/ ~U