The answer is Modus ponens. Modus ponens is firmly identified with another substantial type of contention, modus tollens. Both have clearly comparable yet invalid structures, for example, insisting the subsequent, denying the forerunner, and proof of nonattendance. The productive quandary is the disjunctive adaptation of modus ponens. The speculative syllogism is firmly identified with modus ponens and here and there thought of as "twofold modus ponens."