obversion

listen to the pronunciation of obversion
Английский Язык - Турецкий язык
bir önermeyi ters yönde ifade etme
Английский Язык - Английский Язык
This is also described as "immediate inference by privative conception
{i} reversal; inversion
The act of turning toward or downward
The act of immediate inference, by which we deny the opposite of anything which has been affirmed; as, all men are mortal; then, by obversion, no men are immortal