यस्य विभाषा

That is, a root which is optionally Set, before other affixes, is invariably anit before Nishtha. Thus by 7.2.44, वल् consonant beginning affixes are optionally सेट् after the roots धू &c. The Nishtha after धू &c, will be invariably anit. Thus विधूतः, विधूतवान्; गूढः, गूढवान् ॥ By 7.2.56, the roots having an indicatory उ, optionally are followed by Set क्त्का ॥ The Nishtha after उदित् roots will invariably be anit : as वृद्धः, वृद्धवान् ॥

By the vartika तानि पदि दरिद्राणामुपसंख्यानम् the roots तन्, पत and दरिद्रा take optional इट् in the Desiderative 7.2.49. Though पत् is a root which thus optionally takes इट् in the Desiderative , yet its Nishtha is always सेट्, for Panini himself has employed the word पतित in Sutra 2.1.24, 2.2.38. According to Padamanjari this rule of यस्य विभाषा is anitya and not of universal application. Because had this rule been of universal application then the root कृत which is optionally anit by 7.2.57, would universally anit by the present sutra : and there would be no necessity of reading it with a long ई in the Dhatupatha, as कृती छेदने 6.1.1 to make its nishtha anit under 7.2.14.,