What is 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 called?

contraposition — (Logic) 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. (Webster's 1913.)

Sources