1.简单
补全真值表(1 = 真,0 = 假)。在多少行 N 中 ¬(¬p → (¬p ∧ r)) ∨ (r ∧ q) 为真?
¬(¬p → (¬p ∧ r)) ∨ (r ∧ q)
N =
2.简单
真值表中恰有一行使 b ∨ a 为假。点选这一行。
b ∨ a
- 1a = 1, b = 1
- 2a = 1, b = 0
- 3a = 0, b = 1
- 4a = 0, b = 0
3.中等
哪个公式与 ¬(q ∧ r) 在逻辑上等价?点选它。
¬(q ∧ r)
- 1¬q ∧ r
- 2¬q ∨ ¬r
- 3¬q ∧ ¬r
- 4¬q ∨ r
4.中等
(q ∨ r) ∧ (¬q ∧ ¬r) 是重言式、矛盾式还是偶然式?点选你的答案。
(q ∨ r) ∧ (¬q ∧ ¬r)
- 1重言式
- 2矛盾式
- 3偶然式
5.困难
前提为 r → (p ∨ q); r、结论为 p 的论证是无效的。点选真值表中作为反例的那一行。
r → (p ∨ q)r∴ p
- 1p = 1, q = 1, r = 1
- 2p = 1, q = 1, r = 0
- 3p = 1, q = 0, r = 1
- 4p = 1, q = 0, r = 0
- 5p = 0, q = 1, r = 1
- 6p = 0, q = 1, r = 0
- 7p = 0, q = 0, r = 1
- 8p = 0, q = 0, r = 0
6.困难
前提为 r → q; p → q、结论为 r → p 的论证是无效的。点选真值表中作为反例的那一行。
r → qp → q∴ r → p
- 1p = 1, q = 1, r = 1
- 2p = 1, q = 1, r = 0
- 3p = 1, q = 0, r = 1
- 4p = 1, q = 0, r = 0
- 5p = 0, q = 1, r = 1
- 6p = 0, q = 1, r = 0
- 7p = 0, q = 0, r = 1
- 8p = 0, q = 0, r = 0
答案
- 1. N = 4
- 2. a = 0, b = 0
- 3. ¬q ∨ ¬r
- 4. 矛盾式
- 5. p = 0, q = 1, r = 1
- 6. p = 0, q = 1, r = 1
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