- of or relating to contraposition.
- a contrapositive statement of a proposition.
Origin of contrapositive
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for contrapositive
Every positive in thought has a contrapositive, and the positive and contrapositive are of the same kind.
For a Disjunctive in I., of course, there is no Contrapositive.Logic
In the case of the I proposition the contrapositive is impossible, as infringing the main rule of conversion.
There is an apparent exception to this when the real Middle in an argument is a contrapositive term, not-M.
- placed opposite or against
- a conditional statement derived from another by negating and interchanging antecedent and consequent
- 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
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for contrapositive
Online Etymology Dictionary, © 2010 Douglas Harper