contrapositive

American  

[kon-truh-poz-i-tiv] / ˌkɒn trəˈpɒz ɪ tɪv /

adjective

1. of or relating to contraposition.

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noun

1. a contrapositive statement of a proposition.

contrapositive British  

/ ˌkɒntrəˈpɒzɪtɪv /

adjective

1. placed opposite or against

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noun

1. logic

   1. a conditional statement derived from another by negating and interchanging antecedent and consequent

   2. a categorial proposition obtained from another, esp validly, by any of a number of operations including negation, transferring the terms, changing their quality, and also possibly weakening from universal to particular

Etymology

Origin of contrapositive

First recorded in 1855–60; contraposit(ion) + -ive

Example Sentences

In the case of the I proposition the contrapositive is impossible, as infringing the main rule of conversion.

From Project Gutenberg

Every positive in thought has a contrapositive, and the positive and contrapositive are of the same kind.

From Project Gutenberg

But take the obverse of the contrapositive of both premises: All m is p; All m is s: ∴ Some s is p.

From Project Gutenberg

We will show in this manner that the above is really the contrapositive of the 0 proposition.

From Project Gutenberg

Every impression felt is felt as a change or transition from something else: but it is a variation of the same impression—the something else, the contrapositive, is not entirely different.

From Project Gutenberg