Paniniyashiksha 20

Pāṇinīyaśikṣā 20

saṃvṛtaṃ mātrikaṃ jñeyaṃ vivṛtaṃ tu dvimātrikam
ghoṣā vā saṃvṛtāḥ sarve aghoṣā vivṛtāḥ smṛtāḥ