contraposition

American  

[kon-truh-puh-zish-uhn] / ˌkɒn trə pəˈzɪʃ ən /

noun

1. placement opposite or against.

2. opposition, contrast, or antithesis.

3. Logic. the inference drawn from a proposition by negating its terms and changing their order, as by inferring “Not B implies not A” from “A implies B.”

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contraposition British  

/ ˌkɒntrəpəˈzɪʃən /

noun

1. the act of placing opposite or against, esp in contrast or antithesis

2. logic the derivation of the contrapositive of a given categorial proposition

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Etymology

Origin of contraposition

First recorded in 1545–55, contraposition is from the Late Latin word contrāposition- (stem of contrāpositiō ). See contra ¹, position

Example Sentences

While perhaps a direct contraposition to point number one, it's worth remembering that Doc/Fest is a cross-platform, multimedia festival, as well as being a haven for the factually obsessed.

From The Guardian • May 9, 2013

Paolo Rodari, who writes about the Vatican for the newspaper Il Foglio, said the episode depicted “a widening contraposition happening in the Vatican between Bertone and different clerics who do not like his politics.”

From New York Times • Jan. 27, 2012

The only mode usually recognized of converting a particular negative proposition, is in the form, Some A is not B, therefore something which is not B is A; and this is termed conversion by contraposition.

From A System Of Logic, Ratiocinative And Inductive by Mill, John Stuart

Also if a man is unhappy he could not, from our premisses, by the principles of the syllogism and of contraposition, be dignified—a conclusion which should be fatal to many novelists’ heroes.

From The philosophy of B*rtr*nd R*ss*ll by Various

As applied to disjunctive propositions conversion by contraposition consists simply in transposing the two alternatives.

From Deductive Logic by Stock, St. George William Joseph