obversion noun. [ǝb'vǝ:ʃ(ǝ)n] M19.
[Irreg. from OBVERSE + -ION, after version.]
1. The action of turning towards a person or thing. rare (only in Dicts.). M19.

2. Logic. A form of immediate inference in which the predicate of the contrary of a proposition is negated, so as to obtain another proposition logically equivalent to the original. Also called permutation. L19.

[TahlilGaran] English Dictionary ▲