Natyashastra
आरोहणं च द्विविधं तथा चैवावरोहणम् । न्यासापन्यासविहितं मार्गान्नटकृतं तथा ॥ १८५॥
Ascending and descending are each of two types: one type is prescribed in relation to the Nyāsa and Apanyāsa notes, and the other is applied within the Mārgāntara.
english translation
ArohaNaM ca dvividhaM tathA caivAvarohaNam । nyAsApanyAsavihitaM mArgAnnaTakRtaM tathA ॥ 185॥
hk transliteration by Sanscript