obversion

[ ob-vur-zhuhn, -shuhn ]

noun
  1. an act or instance of obverting.

  2. something that is obverted.

  1. Logic. a form of inference in which a negative proposition is obtained from an affirmative, or vice versa, as “None of us is immortal” is obtained by obversion from “All of us are mortal.”

Origin of obversion

1
1840–50; <Late Latin obversiōn- (stem of obversiō) a turning toward, equivalent to obvers(us) (see obverse) + -iōn--ion

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024