*/
#include "interval.hh"
#include "axis-group-administration.hh"
+#include "axis-group-element.hh"
#include "graphical-element.hh"
#include "debug.hh"
Axis_group_administration::add_element (Graphical_element*e,
Axis_group_element*g, Axis a1, Axis a2)
{
+ // don't add self to self.
+ assert (e != g);
Axis_group_element *& g1 = e->axis_group_l_a_[a1];
Axis_group_element *& g2 = e->axis_group_l_a_[a2];