final boolean unlink(Index<V> succ){
  return !indexesDeletedNode() && casRight(succ,succ.right);
}

final boolean unlink ( Index < V > succ ) { return ! indexesDeletedNode ( ) && casRight ( succ , succ . right ) ; }
tries to cas right field to skip over apparent successor succ . fails ( forcing a retraversal by caller ) if this node is known to be deleted .
