  They developed arguments with them which they called ‘mixed from a hypothetical premise and a probative premise’ (Theophrastus fr. 112A Fortenbaugh). These arguments were inspired by Aristotle’s syllogisms ‘from a hypothesis’ (An. Pr. 1.44); they were forerunners of modus ponens and modus tollens and had the following forms (Theophrastus frs. 111 and 112 Fortenbaugh), employing the exclusive ‘or’: