'The only defining point of the plane. Others can be obtained from the
arbitrary_point method.
See Also
sympy.geometry.point.Point3D
Examples
>>> from sympy import Point3D, Plane
>>> a = Plane(Point3D(1, 1, 1), Point3D(2, 3, 4), Point3D(2, 2, 2))
>>> a.p1
Point3D(1, 1, 1)'

@property
def p1(self):

    return self.args[0]
