Definition of contraposition in English:


Line breaks: contra|pos¦ition
Pronunciation: /kɒntrəpəˈzɪʃ(ə)n


[mass noun] Logic
Conversion of a proposition from all A is B to all not-B is not-A.
More example sentences
  • By contraposition and the definition of the existential quantifier, the latter axiom is equivalent to x = x y (y = x).
  • This means that form and content are not fully unified but retain a structure of abstract contraposition: the content is inscribed in the form while retaining much that cannot be grasped in it.
  • As a contraposition to the conclusions derived from the summation theorem, we have used similar mathematical tools to show that dominance is not an inevitable property of metabolic pathways.


mid 16th century: from late Latin contrapositio(n-), from the verb contraponere, from contra- 'against' + ponere 'to place'.



Pronunciation: /-ˈpɒzɪtɪv/
adjective& noun
More example sentences
  • The contrapositive of the inference is logically equivalent - X simulates Y, X does not have P therefore Y does not - where P is understands Chinese.
  • And you know also the contrapositive, that your being at place X entails that you are not then in a tank on Alpha Centauri.
  • Then the contrapositive not-PN entails not-MN is also true.

Definition of contraposition in:

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Word of the day retroflex
Pronunciation: ˈrɛtrə(ʊ)flɛks
turned backwards