Unformatted text preview: e. Anything that does not exist, cannot be thought about. [= (3) above] In symbols: Tx : x is thought about Ex : x exists : it is possible that … a. 2200 x ( Tx → Ex ) Premise b. 2200 x (¬ Ex → ¬ Ex ) Premise c. 2200 x ( Ex → Ex ) From (b) by contraposition d. 2200 x ( Tx → Ex ) From (a) and (c) by hypothetical syllogism e. 2200 x (¬ Ex → ¬ Tx ) From (d) by contraposition...
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- Fall '09
- Logic, ex, Formal reconstruction