guṇa is substituted for the final ṛ in those roots ending in ṛ in which the vowel is preceded by a conjunct consonant, when the Intensive character yaṅ follows.,
As अरार्यते, सास्वर्यते, दाध्वर्यते, सास्मर्यते ॥ The root ऋ takes यङ् according to a Vartika under Sutra 3.1.22, with Guna we have ऋ + य = अर्य ॥ By 6.1.2, the second member is reduplicated, in spite of the prohibition in 6.1.3, for according to Patanjali र् followed by य is not governed by that prohibition. So we have अर्यर्य, and according to 7.4.60, the य् is dropped, and we have अरर्य, and according to 7.4.60, the य् is dropped, and we have अरर्य, and by 7.4.83, we get अरार्य ॥ This is an exception to 1.1.5.
Vart:- In the Intensive of हन् 'to kill', घ्नी is substituted for हन् as जेघ्नीयते ॥ The substitute is with a long ई, had it been with a short इ, that might also have been lengthened by 7.4.25. Not doing so, however, indicates the existence of the maxim संज्ञापूर्वकविधेरनित्यत्वम् \A rule is not universally valid, when that which is taught in it is denoted by a technical term\. It is through this that स्वायंभुवः is formed from स्वयंभू; because the Guna taught by 6.4.146, does not take place here before the Taddhita affix अण्, in as much as that rule 6.4.146, is taught by employing the technical term गुणः in ओर्गुणः instead of ओरोत्, hence that rule is anitya, and we have उवङ् ॥
Why do we say when meaning 'to kill'? Observe जङ्घन्यते where it means to do.,