Proofs II
Construct proofs for each of the following arguments.
First do these proofs without using conditional or indirect proof. Later, go
back to these and do them with any strategy. Convention: "///" separates
the premises from the conclusion.
Use the general purpose
proof form or do these on paper.
- A
⊃
(B
≡ C), ~B v A,
~(~B v C) /// C
- (L
⊃
R)
⊃ (B & C), ~L &
(M
≡ P), (S
⊃ ~B) /// ~S
- (M v Q), ~(Q v S), (M
⊃
~A) /// (A
⊃ B)
- (L
≡
B), (A & L), ((A & B)
⊃
~C) /// ~C
- (A v (B & C), ((~A
⊃
B)
⊃ D), ~D v (S
≡ Q) ///(~Q
⊃ ~S)
- (A v B)
⊃ (C
&
D), ~D, /// ~A
- (A
≡ B)
⊃ C,
~(C v A), /// B
- (A v B)
⊃
~(C v D), (A & E)
v ~F,
F, /// ~C
- (A & B) v (C
& ~D),
A
⊃
~B, C
⊃
(D v F), /// F
- (P & Q)
⊃ R, (S
& R)
⊃
T, (P & S), (Q v R), /// (R
v
T)
- (F & ~G)
v
(T & ~W), (W
& H), ~(F
⊃ G)
⊃ (H
⊃ ~S), ///
~S
- X
≡ ~Y, (Y
v
Z)
⊃ T, ~(T
v
W), /// P
⊃ X
-
(~A v
~B)
⊃ (~C
v
D), ~C
⊃ (E
& F), E &
~(F v D), ///
A
- F
≡ ~D, D
⊃
C, ~(B v C)
v ~(A v D), A, /// F
v G
- A ⊃
~B, ~C ⊃ B, ~A
⊃ ~C /// A
≡
C
- ~(R & M), ~R
⊃ T, ~M
⊃ O /// T v O