Hayanaratna · by Balabhadra
Chapter 1 · Planets, Signs, Year Entry
ग्रहराशिस्वरूपवर्षप्रवेशाद्यानयनाधिकारः
वसिष्ठसिद्धांतेपि ॥इत्थं माण्डव्य संक्षेपादुक्तं शास्त्रं मयोदितम् ॥विस्रस्ती रविचन्द्राद्यैर्भविष्यति युगे युगे ॥
Also in the Vasishtha Siddhanta: O Mandavya, so I have told you this science in short. In every yuga (age of the world), the Sun, the Moon and the others will slip.
Simple meaning: Vasishtha Siddhanta: in every age the Sun, Moon and planets drift from the old figures.
विस्रंसनं विस्रस्तिः । शिथिलत्वमिति यावत् ॥
The word visrasti: it means slipping or getting loose.
सिद्धान्तसुन्दरेपि॥
When a gap is seen in the sages' figures: correct only that gap, not the whole method.
तदन्तरं बीजसंज्ञब्रह्मगुप्तमकरंदमिश्रादिभिः स्वसत्तादिकाले लक्षयित्वा मुनिशास्त्रजनितेषु ग्रहेषु संस्कृतं तद्युक्तमेव ॥
The correction number: later teachers measured the gap in their own time and added it to the sages' planets. That is right.