99bob.hence

number-of-bottles
  subtract '1' [from] depth

value-of
  get

bottles-remaining
  [compare] value-of 'number-of-bottles' [and] '0'
  [return number of bottles is] greater-than [0]

take-one-down
  decrement-variable 'number-of-bottles'

write-s
    write 's'

write-number-of-bottles
  write value-of 'number-of-bottles'
  write ' bottle'
  [compare] value-of 'number-of-bottles' [and] '1'
  if [number of bottles is] 'not-equal' [to 1] 'write-s' [else] 'do-nothing'
  write [TOS]

write-verse
  write-number-of-bottles ' of beer on the wall, '
  write-number-of-bottles ' of beer.\n'

  write 'Take one down and pass it around, '
  take-one-down
  write-number-of-bottles ' of beer on the wall.\n\n'

main
  reserve '1' [element at bottom-of-stack for number-of-bottles]

  set 'number-of-bottles' [to] '99'
  while 'bottles-remaining' 'write-verse'

  [return] '0'