Both the na-s are changed into ṇa in the reduplicated forms of the verb an , when preceded by an upasarga competent to cause the change.,
Thus in the Desiderative प्राणिणिषति and Aorist of the Causative प्राणिणत्, and so also पराणिणिषति and पराणिणत् ॥
If the maxim पूर्वत्रासिद्धीयमद्विर्वचने be applied here; then we have the following dilemma in, प्रानि + स + ति ॥ Here the affix सन् requires reduplication, and the present sutra requires ण change of न ॥ The णत्व being asiddha, the reduplication being made first, we have प्राणिनि + स + ति, and then the reduplicate ण intervenes between the cause प्र and the root- न् of नि, and so this न would not be changed to ण ॥ If however the above maxim be applied, we first apply the णत्व rule, as प्राणि + स + ति, and then reduplicate णि; and we get the form प्राणिणिषति even without this sutra.
If we could get this form by the application of the above maxim, where is the necessity of the present sutra? The sutra is necessary in order to indicate that the above maxim is anitya or not of universal application. And because it is anitya, that the form औजढत् is evolved by reduplicating हत् (See 8.2.1).,