my @sheads= $t->root->children( 'shead');
  foreach my $shead (@sheads)
    { my $aheadtext= $shead->wrap_in( 'aheadtext');
      my $more_text= $aheadtext->next_sibling;
      while( $more_text->tag ne 'shead')
        { $more_text->move( last_child => $aheadtext);
          $more_text= $aheadtext->next_sibling;
        }
    }