Proofs III
Construct proofs for each of the following theorems using
conditional proof or indirect proof. Use the
general-purpose
proof form or do this on paper.
- A
⊃
(B
⊃ A)
- (C
⊃
D)
≡ (~C v D)
- ((A
⊃ B)
& (B
⊃ A))
⊃
(A
≡
B)
- (C
≡
~D)
⊃
~(C
≡
D)
This one isn't easy!
- ~((A v ~A)
⊃
(A & ~A))
-
~(A & ~B)
⊃
(A
⊃
B)
- A
⊃
(A v ((B v (C
≡ ~R))
& Q)) This looks hard, but it's really easy!
-
(E
⊃ F)
≡
~(~F & E)
- ((~R v S) & (T v ~S))
⊃ (~T
⊃ ~R)
-
[(C v ~D) & (~C & D)]
⊃ [C
≡
~(D & ~C)]
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