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

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horizon. If the Sun's longitude falls short of the longitude
of the Vitribha or exceeds it, there will be parallax in
longitude which will be positive in the former case and
negative in the latter.
Fig. 92
Comm. (Ref. fig. 92) Let SN be the horizon, Z the
zenith and VA the Ecliptic. A is the ascendant or Lagna.
Let V be the point called Vitribha which is 90° behind A.
Strictly speaking V is called Vitribhalagna or lagna from
which three Rāśis or 90° are subtracted (Bha = Rāśi.
त्रिभिर्विरहितम् वित्रिभम्; वित्रिभम् च तत् लग्नम् च वित्रिभलग्नम् ie.
a point whose longitude is got by subtracting three
Rāśis from that of the Lagna). Let ZV be the vertical of
V so that ZV̂A = 90°. It will be seen that AV = 90° as
follows. Let A' be the point where the Ecliptic intersects
the horizon on the west. One will construe that the
Ecliptic is bisected by the meridian; but it is not so.
Spherical triangles AVZ and A'VZ being right-angled at