from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An opposite position; antithesis.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The statement of the form "if not Q then not P", given the statement "if P then Q".
from the GNU version of the Collaborative International Dictionary of English
- n. A placing over against; opposite position.
- n. A so-called immediate inference which consists in denying the original subject of the contradictory predicate; e. g.: Every S is P; therefore, no Not-P is S.
from The Century Dictionary and Cyclopedia
- n. A placing over against; opposite position; in logic, the mode of inference which proceeds by transposing subject and predicate, antecedent and consequent, or premise and conclusion, with negation of the transposed parts.
Sorry, no etymologies found.