Testing equality between objects.
An object fo of this type must provide in addition:

 
For two points.  

 
For two arcs. Two arcs are equal, iff their nonoriented supporting planes are equal, if the centers and squared radii of their respective supporting circles are equal, and if their sources and targets are equal.  

 
For two segments. Two segments are equal, iff their nonoriented supporting lines are equal (i.e. they define the same set of points), and if their endpoints are the same. 
SphericalKernel::CompareX_3
SphericalKernel::CompareY_3
SphericalKernel::CompareZ_3
SphericalKernel::CompareXY_3
SphericalKernel::CompareXYZ_3