popd [ {+|-}n ]
       Removes  a entry from the directory stack, and per-
       form a cd to the new top directory. With  no  argu-
       ment,  the  current top entry is removed.  An argu-
       ment of the form `+n' identifies a stack  entry  by
       counting  from  the  left  of the list shown by the
       dirs command, starting with zero.  An  argument  of
       the   form  -n  counts  from  the  right.   If  the
       PUSHD MINUS option is set, the meanings of `+'  and
       `-' in this context are swapped.
