+ if (Beam* b = dynamic_cast<Beam*> (o))
+ {
+ if (b == beam_l_)
+ {
+ beam_l_ = dynamic_cast<Beam*> (n);
+ if (!beam_l_)
+ {
+ beams_i_drul_[LEFT] = 0;
+ beams_i_drul_[RIGHT] = 0;
+ mult_i_ = 0;
+ }
+ }
+ }
+ Staff_symbol_referencer::do_substitute_element_pointer (o,n);
+