label the missing justifications
a. Derive: A & B
1 A Assumption
2 A ⊃ B Assumption
3 B
4 A & B
1,2 ⊃E
1, 3 &I
1.a. Derive: ∼ G
1 (G ⊃ I) & ∼ I Assumption
1 (G ⊃ I) & ∼ I Assumption
2 G A /∼ I
3 G ⊃ I 1 &E
4 I 2, 3 ⊃E
5 ∼ I 1 &E
6 ∼ G 2–5 ∼ I
1.a. Derive: B ∨ (K ∨ G)
1 K Assumption
1.a. Derive: B ∨ (K ∨ G)
1 K Assumption
2 K ∨ G I ∨I
3 B ∨ (K ∨ G) 2 ∨I
a. Derive: A ⊃ (A ∨ B)
a. Derive: A ⊃ (A ∨ B)
1 A A / ⊃I
2 A ∨ B 1 ∨I
3 A ⊃ (A ∨ B) 1–2 ⊃I
label the missing justifications:
1 A ⊃ (∼ B & ∼ C) Assumption
2 Α
3 ∼ B & ∼ C
4 ∼ B
5 ∼ C
6 ∼ C & ∼ B
7 A ⊃ (∼ C & ∼ B)
A / ⊃Ι
1, 2 ⊃E
3 &E
3 &E
4, 5 &I
1–6 ⊃Ι
c. Derive: ∼ ∼ B
1 ∼ B ⊃ A Assumption
2 ∼ B ⊃ ∼ A Assumption
c. Derive: ∼ ∼ B
1 ∼ B ⊃ A Assumption
2 ∼ B ⊃ ∼ A Assumption
3 ∼ B A /∼ I
4 A 1, 3 ⊃E
5 ∼ A 2, 3 ⊃E
6 ∼ ∼ B 3–5 ∼ I
e. Derive: F
1 ∼ E ∨ F Assumption
2 ∼ E ⊃ F Assumption
e. Derive: F
1 ∼ E ∨ F Assumption
2 ∼ E ⊃ F Assumption
3 ∼ E A / ∨E
4 F 2, 3 ⊃ E
5 F A / ∨E
6 F 5 R
7 F 1, 3–4, 5–6 ∨E
Derive: A ⊃ [B ⊃ (A & B)]
c. Derive: A ⊃ [B ⊃ (A & B)]
1 A A / ⊃I
2 B A / ⊃Ι
3 A & B 1, 2 &I
4 B ⊃ (A & B) 2–3 ⊃I
5 A ⊃ [B ⊃ (A & B)] 1–4 ⊃I
label the missing justifications
Derive: ∼ A ⊃ [Β & (D & C)]
1 ∼ A ⊃ B Assumption
2 B ⊃ D Assumption
3 ∼ A ⊃ C Assumption
4 ∼ A A / ⊃Ι
5 B
6 D
7 C
8 D & C
9 B & (D & C)
10 ∼ A ⊃ [Β & (D & C)]
1, 4 ⊃E
2, 5 ⊃E
3, 6 ⊃E
6, 7 &I
5, 8 &I
4–9 ⊃I
e. Derive: A
1 (∼ A ⊃ ∼ B)& (∼ B ⊃ B) Assumption
e. Derive: A
1 (∼ A ⊃ ∼ B)& (∼ B ⊃ B) Assumption
2 ∼ A A /∼ E
3 ∼ A ⊃ ∼ B 1 &E
4 ∼ B 2, 3 ⊃E
5 ∼ B ⊃ B 1 &E
6 B 4, 5 ⊃E
7 A 2–6 ∼ E
e. Derive: E TRIPLE BAR O
1 (E ⊃ T) & (T ⊃ O) Assumption
2 O ⊃ E Assumption
e. Derive: E TRIPLE BAR O
1 (E ⊃ T) & (T ⊃ O) Assumption
2 O ⊃ E Assumption
3 E A / I
4 E ⊃ T 1 &E
5 T 3, 4 ⊃E
6 T ⊃ O 1 &E
7 O 5, 6 ⊃E
8 O A / I
9 E 2, 8 ⊃E
10 E O 3–7, 8–9 I
g. Derive: (A ⊃ B) ⊃ [(C ⊃ A) ⊃ (C ⊃ B)]
g. Derive: (A ⊃ B) ⊃ [(C ⊃ A) ⊃ (C ⊃ B)]
1 A ⊃ B A / ⊃I
2 C ⊃ A A / ⊃I
3 C A / ⊃I
4 A 2, 3 ⊃E
5 B 1, 4 ⊃E
6 C ⊃ B 3–5 ⊃I
7 (C ⊃ A) ⊃ (C ⊃ B) 2–6 ⊃I
8 (A ⊃ B) ⊃ [(C ⊃ A) ⊃ (C ⊃ B)] 1–7 ⊃I
label the missing justifications
k. Derive: (A & B) ⊃ (C & D)
1 (B & A) ⊃ (D & C) Assumption
2 A & B A / ⊃I
3 B
4 A
5 B & A
6 D & C
7 C
8 D
9 C & D
10 (A & B) ⊃ (C & D)
2 &E
2 &E
3, 4 &I
1, 5 ⊃E
6 &E
6 &E
7, 8 &I
2–9 ⊃I
i. Derive: A ⊃ (B ⊃ C)
1 (A & B) ⊃ C Assumption
i. Derive: A ⊃ (B ⊃ C)
1 (A & B) ⊃ C Assumption
2 A A / ⊃Ι
3 B A / ⊃Ι
4 A & B 2, 3 & I
5 C 1, 4 ⊃E
6 B ⊃ C 3–5 ⊃I
7 A ⊃ (B ⊃ C) 2–6 ⊃I
Derive: D ⊃ B
1 A ⊃ C Assumption
2 (∼ A ∨ C) ⊃ (D ⊃ B) Assumption
Derive: D ⊃ B
1 A ⊃ C Assumption
2 (∼ A ∨ C) ⊃ (D ⊃ B) Assumption
3 ∼ (∼ A ∨ C) A /∼ E
4 A A /∼ I
5 C 1, 4 ⊃E
6 ∼ A ∨ C 5 ∨I
7 ∼ (∼ A ∨ C) 3 R
8 ∼ A 4–7 ∼I
9 ∼ A ∨ C 8 ∨I
10 ∼ (∼ A ∨ C) 3 R
11 ∼ A ∨ C 3, 10 ∼ E
12 D ⊃ B 2, 11 ⊃E
k. Derive: A ⊃ [B ⊃ (A ⊃ B)]
k. Derive: A ⊃ [B ⊃ (A ⊃ B)]
1 A A / ⊃I
2 B A / ⊃I
3 A A / ⊃I
4 B 2 R
5 A ⊃ B 3–4 ⊃I
6 B ⊃ (A ⊃ B) 2–5 ⊃I
7 A ⊃ [B ⊃ (A ⊃ B)] 1–6 ⊃I
label the missing justifications
Derive: (A & B) ⊃ E
1 A ⊃ C Assumption
2 B ⊃ D Assumption
3 (C & D) ⊃ E Assumption
4 A & B A / ⊃I
5 A
6 B
7 C
8 D
9 C & D
10 E
11 (A & B) ⊃ E
4 &E
4 &E
1, 5 ⊃E
2, 6 ⊃E
7, 8 &I
3, 9 ⊃E
4–10 ⊃1
c. Derive: D ∨ E
1 E ∨ D Assumption
c. Derive: D ∨ E
1 E ∨ D Assumption
2 E A / ∨E
3 D ∨ E 2 ∨I
4 D A / ∨E
5 D ∨ E 4 ∨ I
6 D ∨ E 1, 2–3, 4–5 ∨E
Derive: B ∨ ∼ C
1 A ∨ (B & C) Assumption
2 C ⊃ ∼ A Assumption
Derive: B ∨ ∼ C
1 A ∨ (B & C) Assumption
2 C ⊃ ∼ A Assumption
3 A A / ∨E
4 C A /∼ I
5 ∼ A 2, 4 ⊃E
6 A 3 R
7 ∼ C 4–6 ∼ 1
8 B ∨ ∼ C 7 ∨I
9 B & C A / ∨E
10 B 9 &E
11 B ∨ ∼ C 10 ∨I
12 B ∨ ∼ C 1, 3–8, 9–11 ∨E
Derive: A ∨ (B & C)
Derive: A ∨ (B & C)
1 (A ∨ B) & (A ∨ C) Assumption
2 A ∨ B 1 &E
3 A A / ∨E
4 A ∨ (B & C) 3 ∨I
5 B A / ∨E
6 A ∨ C 1 &E
7 A A / ∨E
8 A ∨ (B & C) 7 ∨I
9 C A / ∨E
10 B & C 5, 9 &I
11 A ∨ (B & C) 10 ∨I
12 A ∨ (B & C) 6, 7–8, 9–11 ∨E
13 A ∨ (B & C) 2, 3–4, 5–12 ∨E