1. Therefore, by contraposition k must be a power of 2. 2. Strictly speaking, a contraposition can only exist in two simple conditionals. 3. There is a corollary contraposition in the preceding sentences. 4. The contraposition with De Gasperi was very clear. 5. See also contraposition and proof by contrapositive. 6. However, a contraposition may also exist in two complex conditionals, if they are similar. 7. The slogan is often found in contraposition : " The political is personal ". 8. Therefore, by contraposition , a necessary condition for unit treatment additivity is that the variance is constant. 9. The elections will have a bipolar character, and will be dominated by the contraposition of two political groupings, 10. Therefore, by contraposition , a necessary condition for unit-treatment additivity is that the variance is constant.