at_top          Return TRUE if current member is top member.

at_end          Return TRUE if current member is last member.

is_empty        Return TRUE if LIST is empty, FALSE otherwise.

find            Search the list for an implementation defined member.
                If not found don't change currency.

prev            Make the member previous to this one current. If current
                member is top, do nothing.

next            Make the member after this one current. If current
                member is last, do nothing.

seek            Search to a position in the list. Use like fseek.

top             Make the top member current.

end             Make the last member current.

display         Display the current member.

add_member      Add a new member to the list.

replace_member  Replace data in current member.

current         Return a pointer to the current member.

total_members   Return the total number of members int the list.

tell            Return the position, from the start of the list of
                the current member. The top member is 0.