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

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Dakṣina Sankutala + Uttara Bhuja, since A₂ C₂ =
B₂ A₂ + B₂ C₂. In the absence of a unifying convention,
all these formulae are loose and apt to create confu-
sion. So we shall unify all these formulae into the
standard form A=S+B which holds good universally, if
we have the conventions.
(1) Agrā shall be deemed positive if it be north and
negative if it be south ;
(2) Similarly with respect to the Bhuja. But, with
respect to the Śankutala, we shall deem it positive if it be
south and negative if north. These conventions compre-
hend all the cases and unify them into the standard form
A=S+B. The corresponding conventions with respect
to δ, a are that +δ corresponds to Uttarāgrā and +a
corresponds to Uttara Bhuja.
Having the above conventions, and finding the Bhujas
of the Moon above the horizon and the Sun below the
horizon, the Spaṣṭa Bhuja required in finding the Śṛṅgon-
nati in the present chapter, is defined as the difference of
the Bhujas of the Sun and the Moon and the sum thereof
according as they are of the same direction north or south
or of different directions. Also this Spaṣṭa Bhuja is by
convention said to have the same direction as that of the
Moon. If, however, the Bhuja of the Moon falls short of
that of the Sun, then the Spaṣṭa Bhuja is said to have the
direction opposite to that of the Moon.
Verse (4). Definition of Koti.
I deem that the Koti should be taken as the sum
of the Śankus of the Sun and the Moon, the one being
below the horizon and the other above respectively.
Comm. We have defined above the Spaṣṭa Bhuja as
the north-south distance between the feet of the Śankus