anchor.diff:  
   header d2/
   : d2/
  -    >r 1 rshift r@
  +    >r d# 1 rshift r@
       d# 31 lshift
       or r> 2/
   ;
  
positive.code:     
  ;
  
  header-imm 2literal
  : 2literal
      swap tliteral tliteral
  ;
  
  header-imm postpone
  
negative.code:     d# 32
  ;
  
  : hex8 dup d# 16 rshift DOUBLE
  : hex4 dup d# 8 rshift DOUBLE
  : hex2 dup d# 4 rshift DOUBLE
  : hex1
      h# f and
      dup d# 10 < if
  