- Stem* s = (Stem*)i.elem_l_->access_Item ();
- if (!i.req_l_ || !i.req_l_->access_Musical_req () || !i.req_l_->access_Musical_req ()->access_Rhythmic_req ())
+ Stem* s = (Stem*)dynamic_cast <Item *> (i.elem_l_);
+ if (!dynamic_cast <Rhythmic_req *> (i.req_l_))