list
lists

    A data structure holding many values, possibly of
   different types, which is usually accessed sequentially,
   working from the head to the end of the tail - an "ordered
   list".  This contrasts with a (one-dimensional) array, any
   element of which can be accessed equally quickly.

   Lists are often stored using a cell and pointer arrangement
   where each value is stored in a cell along with an associated
   pointer to the next cell.  A special pointer, e.g. zero, marks
   the end of the list.  This is known as a (singly) "linked
   list".  A doubly linked list has pointers from each cell to
   both next and previous cells.

   An unordered list is a set.

   (1998-11-12)