Surya Siddhanta
शोध्यम् चन्द्राद् गते पाते तत्सूर्यगतिताडितम् । चन्द्रभुक्त्या हृतम् भानौ लिप्तादि शशिवत् फलम्॥
And is to be subtracted from the moon's longitude when the aspect is past. If the same quantity be multiplied by the eun's motion and divided by the moon's motion, the result is an equation, in minutes, which is to be applied to the sun's place, in the same direction as the other to the moon's.
english translation