: cons ( y x -- pair )  2 cells allocate throw  dup >r  2!  r> ;

: >car ( pair -- first-addr ) ; immediate
: >cdr ( pair -- second-addr )  cell+ ;

: car  ( pair -- first )   >car @ ;
: cdr  ( pair -- second )  >cdr @ ;

: linked-list ( -- list )  nil nil cons ;

: add-node ( list node -- )  over @  swap cons  swap ! ;