     // hide the hidden ones     if(step.hidden)       continue;      switch(step.type)     {     case goto_trace_stept::typet::ASSERT:       if(!step.cond_value)       {         out << '\n';         out << messaget::red << "Violated property:" << messaget::reset << '\n';         if(!step.pc->source_location.is_nil())           out << "  " << state_location(step, ns) << '\n';          out << "  " << messaget::red << step.comment << messaget::reset << '\n';          if(step.pc->is_assert())         {           out << "  "               << from_expr(ns, step.function_id, step.pc->get_condition())               << '\n';         }          out << '\n';       }       break;      case goto_trace_stept::typet::ASSIGNMENT:       if(