सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

next Sun-rise, T₃ the ending moment of the tithi preceding
the Sun-rise R₄ upto which point the Ahargaṇa has to
be found from the commencement of the Solar year. Thus
the Ahargaṇa to be found is SR₄ = ST₃ + T₃ R₄. Here
T₃ R₄ is the Kshayāghatis, at the Sun-rise concerned.
SR₃ is a fraction of a day that is to be there in the Ahar-
gaṇa SR₄ we are seeking. While subtracting the Śuddhi
T₁ S diminished by the Kshayāghatis T₂ R₃ from the
number of elapsed integral number of tithis from the
commencement of the luni-Solar year namely T₁ T₃ we
have T₁ T₃ — (T₁ S — T₂ R₃) = T₁ T₃ — (T₁ T₂ — SR₃) =
T₂ T₃ + SR₃. Thus instead of SR₃ + R₃ R₄ we have by
the above procedure SR₃ + T₂ T₃. Though both T₂ T₃ and
R₃ R₄ are integral numbers and should be the same if the
interval is small, they may differ by an integral number,
if the interval happens to be long. Bhaskara says that
this difference of an integral number will be rectified by
the Kshepadinas found under verse No. 12, for, from these
Kshepadinas, the Kshayāhas are found and subtracted
from the tithis. It will be noted that the difference of
an integral number between T₂ T₃ and R₃ R₄ is no other
than Kshayāhas.
Or, this may be seen in an other way. We are to find
SR₄ = T₁ R₄ — T₁ S = T₁ T₃ + T₃ R₄ — T₁ S = T₁ T₃ —
(T₁ S — T₃ R₄) = No. of elapsed tithis — (Suddhi —
Kshayaghatis at the day concerned). But instead of the
Kshayaghatis at the day concerned Bhaskara prescribes
the subtraction of the Kshayāghatis at the end of the Solar
year ie instead of subtracting T₃ R₄ it is prescribed to sub-
tract T₂ R₃. This difference, Bhaskara says is made up
by taking into account the Kshepadinas pertaining to the
Kshayāhas.
Verse 14. In case the Ahargaṇa is required for a day
preceeding the commencement of the Solar year, then the
elapsed tithis are less than the Tithis of the Suddhi; so
subtraction is not feasible. In this case, it is prescribed