Virtual HW #6

Reminder: Each HW problem solution should consist of:

• a restatement of the entire problem (you may copy it word for word),
• followed by a complete solution with all intermediate steps shown.

Exercises are from §1.6, p. 85 (introduction to proofs).

1. #6
   • Hint: Odd(n) =def ∃x[n = 2x + 1]

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2. #16
   • Suggestion: Try Proof by Contraposition.
     Hint: You may appeal to problem #6, above.

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3. #18ab

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4. #22
   • Suggestion: The instructor's answer manual suggests using Proof by Contradiction.
                           But I think you might find it easier to try using Proof by Cases (see pp. 86-90).