LIB_US_MONEY [
  
  ; fifty, fifty three dollars even, one hundred dollars
  ( SUB_DOLLAR_OPTIONAL_AMOUNT:d ?SUB_EVEN
  ) {return([<dollars $d>])}

  ; one fifty even
  ( SUB_DIGIT_ONE_THRU_NINE:h SUB_MONEY_THRU_99_WITH_OH:u SUB_EVEN
  ) {return([<dollars add(mul(100 $h) $u)>])}
  
  ; two bucks, a hundred bucks (small and round amounts only)
  SUB_BUCKS_AMOUNT:d {return([<dollars $d>])}
  
  ; a buck twenty five (only place buck is allowed with non-zero cents)
  ( a buck SUB_MONEY_THRU_99:c ) {return([<dollars 1> <cents $c>])}

  ; sixty two cents, no dollars and nine cents
  ( ?( [ no zero ] ?( dollars ?and ) ) 
    SUB_MONEY_THRU_99:c cents 
  ) {return([<cents $c>])}
  
  ; one cent
  ( ?( [ no zero ] ?( dollars ?and ) ) 
    one cent 
  ) {return([<cents 1>])}
  
  ; five dollars and twenty seven cents, four dollars thirty cents
  ( SUB_DOLLAR_REQUIRED_AMOUNT:d ?and SUB_MONEY_THRU_99:c cents 
  ) {return([<dollars $d> <cents $c>])}
  
  ; five dollars and one cent, four dollars one cent
  ( SUB_DOLLAR_REQUIRED_AMOUNT:d ?and one cent 
  ) {return([<dollars $d> <cents 1>])}

  ; forty two oh six
  ( SUB_MONEY_THRU_99:d SUB_MONEY_THRU_99_WITH_OH:c 
  ) {return([<dollars $d> <cents $c>])}

  ; one hundred seventeen twenty
  ( SUB_DIGIT_ONE_THRU_NINE:h hundred ?and SUB_MONEY_THRU_99:u
    SUB_MONEY_THRU_99_WITH_OH:c 
  ) {return([<dollars add(mul(100 $h) $u)> <cents $c>])}
  
  ; five thirty four fifty, one oh four ninety nine
  ( SUB_DIGIT_ONE_THRU_NINE:h SUB_MONEY_THRU_99_WITH_OH:u 
    SUB_MONEY_THRU_99_WITH_OH:c
  ) {return([<dollars add(mul(100 $h) $u)> <cents $c>])}
  
  ; ten million dollars, just to make the end point a round number
  ( ten million [ dollars bucks ] ) {return([<dollars 10000000>])}
]

SUB_DOLLAR_REQUIRED_AMOUNT [
  ( [ a one ] dollar ) {return(1)}
  ( SUB_DOLLARS_AMOUNT:d dollars ) {return($d)}
]

SUB_DOLLAR_OPTIONAL_AMOUNT [
  ( one ?dollar ) {return(1)}
  ( a dollar ) {return(1)}
  ( SUB_DOLLARS_AMOUNT:d ?dollars ) {return($d)}
]

SUB_DOLLARS_AMOUNT [
  ( ?a hundred ) {return(100)}
  ( ?a thousand ) {return(1000)}
  ( ?a million ) {return(1000000)}

  SUB_MONEY_THRU_999:d {return($d)}

  ( SUB_MONEY_THRU_999:t thousand ) {return(mul(1000 $t))}
  ( SUB_MONEY_THRU_999:t thousand 
    SUB_MONEY_THRU_999:u
  ) {return(add(mul(1000 $t) $u))}
  
  ( SUB_TEEN:h hundred ) {return(mul(100 $h))}
  ( SUB_DECADE:t SUB_DIGIT_ONE_THRU_NINE:h hundred 
  ) {return(mul(100 add($t $h)))}
    
  ( SUB_TEEN:h hundred ?and SUB_MONEY_THRU_99:u 
  ) {return(add(mul(100 $h) $u))}
  ( SUB_DECADE:t SUB_DIGIT_ONE_THRU_NINE:h hundred ?and 
    SUB_MONEY_THRU_99:u
  ) {return(add(mul(100 add($t $h)) $u))}

  ( SUB_DIGIT_ONE_THRU_NINE:m million ) {return(mul(1000000 $m))}
  ( SUB_DIGIT_ONE_THRU_NINE:m million
    SUB_MONEY_THRU_999:u
  ) {return(add(mul(1000000 $m) $u))}
  ( SUB_DIGIT_ONE_THRU_NINE:m million
    SUB_MONEY_THRU_999:t thousand
  ) {return(add(mul(1000000 $m) mul(1000 $t)))}
  ( SUB_DIGIT_ONE_THRU_NINE:m million
    SUB_MONEY_THRU_999:t thousand 
    SUB_MONEY_THRU_999:u
  ) {return(add(mul(1000000 $m) add(mul(1000 $t) $u)))}
]

SUB_BUCKS_AMOUNT [
  ( SUB_MONEY_THRU_999:d bucks ) {return($d)}

  ( a hundred bucks ) {return(100)}
  ( SUB_TEEN:h hundred bucks ) {return(mul(100 $h))}
  ( SUB_DECADE:t SUB_DIGIT_ONE_THRU_NINE:h hundred bucks
  ) {return(mul(100 add($t $h)))}

  ( a thousand bucks ) {return(1000)}
  ( [ SUB_DIGIT_ONE_THRU_NINE:h 
      SUB_TEEN:h
    ] 
    thousand bucks 
  ) {return(mul(1000 $h))}
  ( SUB_DECADE:t SUB_DIGIT_ONE_THRU_NINE:h thousand bucks
  ) {return(mul(1000 add($t $h)))}
  
  ( a million bucks ) {return(1000000)}
  ( SUB_DIGIT_ONE_THRU_NINE:m million bucks 
  ) {return(mul(1000000 $m))}
]    

SUB_MONEY_THRU_999 [
   SUB_MONEY_THRU_99:d {return($d)}
  ( SUB_DIGIT_ONE_THRU_NINE:h hundred ) {return(mul(100 $h))}
  ( SUB_DIGIT_ONE_THRU_NINE:h hundred ?and SUB_MONEY_THRU_99:u
  ) {return(add(mul(100 $h) $u))}
]

SUB_MONEY_THRU_99 [
  SUB_DIGIT_ONE_THRU_NINE:d {return($d)}
  SUB_TEEN:d {return($d)}
  ten {return(10)}
  SUB_DECADE:t {return($t)}
  ( SUB_DECADE:t SUB_DIGIT_ONE_THRU_NINE:u ) {return(add($t $u))}
]

SUB_MONEY_THRU_99_WITH_OH [
  ( oh SUB_DIGIT_ONE_THRU_NINE:n ) {return($n)}
  SUB_TEEN:n {return($n)}
  ten {return(10)}
  SUB_DECADE:t {return($t)}
  ( SUB_DECADE:t SUB_DIGIT_ONE_THRU_NINE:u ) {return(add($t $u))}
]

SUB_EVEN [
  even
  exactly
  ( ?point [ no zero ] cents ) 
]

SUB_DIGIT_TWO_THRU_NINE [
  two {return(2)}
  three {return(3)}
  four {return(4)}
  five {return(5)}
  six {return(6)}
  seven {return(7)}
  eight {return(8)}
  nine {return(9)}
]

SUB_DIGIT_ONE_THRU_NINE [
  one {return(1)}
  SUB_DIGIT_TWO_THRU_NINE:n {return($n)}
]

SUB_DIGIT [
  [ zero oh ] {return(0)}
  SUB_DIGIT_ONE_THRU_NINE:n {return($n)}
]

; Single-digit grammars that return string values

SUB_DIGIT_TWO_THRU_NINE_STRING [
  two {return("2")}
  three {return("3")}
  four {return("4")}
  five {return("5")}
  six {return("6")}
  seven {return("7")}
  eight {return("8")}
  nine {return("9")}
]

SUB_DIGIT_ONE_THRU_NINE_STRING [
  one {return("1")}
  SUB_DIGIT_TWO_THRU_NINE_STRING:n {return($n)}
]

SUB_DIGIT_STRING [
  [ zero oh ] {return("0")}
  SUB_DIGIT_ONE_THRU_NINE_STRING:n {return($n)}
]

SUB_TEEN_STRING [
  eleven {return("11")}
  twelve {return("12")}
  thirteen {return("13")}
  fourteen {return("14")}
  fifteen {return("15")}
  sixteen {return("16")}
  seventeen {return("17")}
  eighteen {return("18")}
  nineteen {return("19")}
]

SUB_DECADE_STRING [
  twenty {return("2")}
  thirty {return("3")}
  forty {return("4")}
  fifty {return("5")}
  sixty {return("6")}
  seventy {return("7")}
  eighty {return("8")}
  ninety {return("9")}
]

SUB_TEEN [
  eleven {return(11)}
  twelve {return(12)}
  thirteen {return(13)}
  fourteen {return(14)}
  fifteen {return(15)}
  sixteen {return(16)}
  seventeen {return(17)}
  eighteen {return(18)}
  nineteen {return(19)}
]

SUB_DECADE [
  twenty {return(20)}
  thirty {return(30)}
  forty {return(40)}
  fifty {return(50)}
  sixty {return(60)}
  seventy {return(70)}
  eighty {return(80)}
  ninety {return(90)}
]