                          <0>              <0>               p
                        _'   \           _'   \             <->
         <0>           <0>    <0>        p     <0>        _'   \
       _'   \    =>  _'           =>    <->        =>    <->    <0>
      <0>    <0>     n                _'               _'
                    <0>               n                n
                                     <0>              <0>
 
