Definition of "contraposition"

contraposition

noun
countable and uncountable, plural contrapositions
1. (countable, logic) The statement of the form "if not Q then not P", given the statement "if P then Q".
2. Opposition; contrast.
  Quotations
  The expression “Allon” indicates the unique character of this relationship: that of being together in contraposition. I belong to the Allon, and yet detach myself from it.
  2012, Erwin W. Straus, Maurice Natanson, Henri Ey, Psychiatry and Philosophy, page 76