F T T T F F F T F T F T T T F F F F T F T F T T F F F F T T T F √ 7. Let = and = E X is an even number, D X is divisible by 2. E D E D ~ D / ~ E T T T F F T F F T F F T T F T F F T T T 8. Valid. Let = and let = E X is an even number, D X is divisible by 2. E D ~ E ~ D D / E T T F T F T T T F F T T F T F T T F F T F F F T T T F F 9. Invalid. Let = and = J Joyce went south on 1-15 from Las Vegas, L Joyce got to Los Angeles. J L J L ~ J / ~ L T T T F F T F F F T F T T T F √ F F T T T 10. Invalid. Let = and = F you did finish the job by Friday, B you did get the bonus. F B ~ F ~ B F / B T T F T F T T T F F T T T F √ F T T F F F T F F T T T F F 11. Invalid. Let = and = F you did finish the job by Friday, B you did get the bonus. F B F B ~ F / ~ B T T T F F T F F F T F T T T F √ F F T T T 12. Valid. Let = and = E Eddie can vote, R he (Eddie) is registered. E R E R R / E ≡
F T T T F F F T F T F T T T F F F F T F T F T T F F F F T T T F √ 7. Let E = X is an even number, and D = X is divisible by 2. E D E D ~ D / ~ E T T T F F T F F T F F T T F T F F T T T 8. Valid. Let E = X is an even number, and let D = X is divisible by 2. E D ~ E ~ D D / E T T F T F T T T F F T T F T F T T F F T F F F T T T F F 9. Invalid. Let J = Joyce went south on 1-15 from Las Vegas, and L = Joyce got to Los Angeles. J L J L ~ J / ~ L T T T F F T F F F T F T T T F √ F F T T T 10. Invalid. Let F = you did finish the job by Friday, and B = you did get the bonus. F B ~ F ~ B F / B T T F T F T T T F F T T T F √ F T T F F F T F F T T T F F 11. Invalid. Let F = you did finish the job by Friday, and B = you did get the bonus. F B F B ~ F / ~ B T T T F F T F F F T F T T T F √ F F T T T 12. Valid. Let E = Eddie can vote, and R = he (Eddie) is registered. E R E ≡ R R / E