contraposition

 
Pronunciation: /kɒntrəpəˈzɪʃ(ə)n/

noun

[mass noun] Logic
  • conversion of a proposition from all A is B to all not-B is not-A.

Derivatives

contrapositive

Pronunciation: /-ˈpɒzɪtɪv/
adjective & noun

Origin:

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