Analyze each sentence below in as much detail as possible, presenting the result in both symbols and English notation (using both ... and, etc., as well as ∧, etc.). Be sure that the unanalyzed components of your answer are complete and independent sentences; also try to respect any grouping in the English. |
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1. |
Sam was cool, but he was not both calm and collected. answer |
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2. |
Tom spoke to either Al or Barb but to neither Carol nor Dave. answer |
Synthesize an English sentence (the more idiomatic the better) that has the following analysis: |
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3. |
¬ E ∨ F (E: Ed worked last weekend; F: Fred worked last weekend) answer |
Use derivations to check whether each of the entailments below holds. If one fails, present a counterexample by providing a table in which you calculate the truth values of the premises and conclusion on an extensional interpretation (i.e., an assignment of truth values) that divides an open gap. |
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Do not use attachment or detachment rules in 4-6. That is, do not use Adj or the rules MTP, MPT, and Wk of §4.3; instead use only the basic rules for exploiting resources, planning for goals, and closing gaps. |
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4. |
A ∧ B ⊨ ¬ (C ∧ ¬ B)
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5. |
¬ (A ∧ B), ¬ A ⊨ B
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6. |
C, A ∨ B ⊨ A ∨ (B ∧ C)
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In 7 you may use attachment and detachment rules (and their use can simplify the derivation). |
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7. |
¬ (A ∧ C), A ∨ B ⊨ B ∨ ¬ C
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4. |
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6. |
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7. |
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