: WORD(
    DUP 1- C@   ( name len field )
    127 AND     ( 0x7f. remove IMMEDIATE flag )
    3 +         ( fixed header len )
    -
;
: FORGET
    ' DUP               ( w w )
    ( HERE must be at the end of prev's word, that is, at the
      beginning of w. )
    WORD( HERE !  ( w )
    PREV CURRENT !
;
: EMPTY LIT< _sys FIND IF DUP HERE ! CURRENT ! THEN ;