(In those tenses which are marked with an indicatory ṅ ) jus is the substitute of jhi when it comes after an luṅ (Aorist) in sic or the laṅ (Imperfect Tense) of a reduplicated verb or the root vid 'to know'.,
This applies to tenses having ङ् other than that of लिङ्, namely, the लङ् and लुङ् ।
सिच् is employed in forming the first Aorist. The reduplicated verbs, as well as the verb विद्, form their third person plural in जुस्, in the tenses other than लिङ्, and those that take सिच् । The word ङितः of sutra 3.4.99, is understood here also; and therefore this rule is restricted to the Imperfect (लङ्) of the reduplicated verb. Thus of सिच्, we have अकार्षुः, अहार्षः । Similarly, after the Imperfect of the reduplicated verbs, we have अविभयुः, अजिहयुः, अजागरुः । In the case of विद्, we have अविदुः ।,