DEFINE units ==
[ "zero" "one" "two" "three" "four" "five" "six" "seven" "eight" "nine" "ten"
  "eleven" "twelve" "thirteen" "fourteen" "fifteen" "sixteen" "seventeen"
  "eighteen" "nineteen" ];

tens ==
[ "ten" "twenty" "thirty" "forty" "fifty" "sixty" "seventy" "eighty" "ninety" ];

convert6 ==
[1000000 <]
[1000 div swap convert " thousand " putchars convert3]
[1000000 div swap convert " million " putchars convert3]
ifte;

convert5 ==
[null]
[]
[" and " putchars convert]
ifte;

convert4 ==
[1000 <]
[100 div swap units of putchars " hundred" putchars convert5]
[convert6]
ifte;

convert3 ==
[null]
[]
[32 putch convert]
ifte;

convert2 ==
[100 <]
[10 div swap pred tens of putchars convert3]
[convert4]
ifte;

convert ==
[20 <]
[units of putchars]
[convert2]
ifte.