 Later theoretical elaborations by Dignāga, Dharmakīrti, et al. about how to present publicly (i.e., verbally) a good reason (saddhetu) to an adversary in a debate prescribe the use of complex verbal forms known as prayoga (formal reasonings). Thus, for example, the standard formal reasoning that Dharmakīrti and his Indo-Tibetan successors prescribed was a two-membered form, known as an “inference-for-others” (parārthānumāna):