( LITN has to be defined after the last immediate usage of
  it to avoid bootstrapping issues )
: LITN 32 , , ( 32 == NUMBER ) ;

: IMMED? 1- C@ 0x80 AND ;

( ';' can't have its name right away because, when created, it
  is not an IMMEDIATE yet and will not be treated properly by
  xcomp. )
: _
    ['] EXIT ,
    R> DROP     ( exit : )
; IMMEDIATE