SCM vissym = ly_symbol2scm ("break-visibility");
SCM vis = bars_[0]->internal_get_property (vissym);
if (ly_is_equal (spanbar_->internal_get_property (vissym), vis))
SCM vissym = ly_symbol2scm ("break-visibility");
SCM vis = bars_[0]->internal_get_property (vissym);
if (ly_is_equal (spanbar_->internal_get_property (vissym), vis))