CircularKernel::Split_2

A model fo of this type must provide:

void
fo ( CircularKernel::Circular_arc_2 a ,
CircularKernel::Circular_arc_point_2 p ,
CircularKernel::Circular_arc_2 &a1 ,
CircularKernel::Circular_arc_2 &a2 )
Splits arc a at point p, which creates arcs a1 and a2.

void
fo ( CircularKernel::Line_arc_2 l ,
CircularKernel::Circular_arc_point_2 p ,
CircularKernel::Line_arc_2 &l1 ,
CircularKernel::Line_arc_2 &l2 )
Same for a line arc.