CREDIT_CARD_EXPIRATION
[
VLIB_CREDIT_CARD_EXPIRATION:z  {< choice $z>}
]



VLIB_CREDIT_CARD_EXPIRATION [
  ( ?[ ( ?( ?it's [ valid good ] ) ?up [ through til until ] )
      ( it expires )
      ( the expiration ?date is )
      ( the date is )
      it's
    ]
    ?[ ( the 
        [ end 
          ( [ last ( twenty [ eighth ninth ] ) thirtieth ( thirty first ) ]
            ?day
          )
        ] 
        of
      )
      ( twenty [ eight nine ] )
      ( thirty ?one )
    ]
    VSUB_CREDIT_CARD_DATE_MONTH_NAME:m
    ?of
    VSUB_CREDIT_CARD_DATE_YEAR:y
  )
  ( VSUB_CREDIT_CARD_MONTH_NUMBER_AS_DIGIT:m 
    ?[ ( [ two twenty ] [ eight nine ] ) 
       ( thirty ?one )
       ( three [ zero oh one ] ) 
     ]
    VSUB_CREDIT_CARD_DATE_YEAR:y 
  )
] {return (strcat($m strcat(", " $y)))}


; ] {return([<month $m> <year $y>])}

VSUB_CREDIT_CARD_MONTH_NUMBER [
  ( ?[ zero oh ] VSUB_DIGIT_ONE_THRU_NINE:n ) {return($n)}
  ten {return(10)}
  eleven {return(11)}
  twelve {return(12)}
]

VSUB_CREDIT_CARD_MONTH_NUMBER_AS_DIGIT [
  ( [ zero oh ] VSUB_DIGIT_ONE_THRU_NINE:n ) {return($n)}
  ( one [ zero oh ] ) {return(10)}
  ( one one ) {return(11)}
  ( one two ) {return(12)}
]

VSUB_CREDIT_CARD_DATE_MONTH_NAME [
  january {return(1)}
  february {return(2)}
  march {return(3)}
  april {return(4)}
  may {return(5)}
  june {return(6)}
  july {return(7)}
  august {return(8)}
  september {return(9)}
  october {return(10)}
  november {return(11)}
  december {return(12)}
]

VSUB_CREDIT_CARD_DATE_YEAR [
  ( ?( nineteen ?( hundred ?and ) ) ninety nine ) {return(1999)}
  ( ?( the year ) two thousand ) {return(2000)}
  ( double zero ) {return(2000)}
  ( [ ( two thousand ?and ) ( twenty oh ) ]
    VSUB_DIGIT_ONE_THRU_NINE:n
  ) {return(add(2000 $n))}
  ( [ zero oh ] VSUB_DIGIT_ONE_THRU_NINE:n
  ) {return(add(2000 $n))}
]

VSUB_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)}
]

VSUB_DIGIT_ONE_THRU_NINE [
  one {return(1)}
  VSUB_DIGIT_TWO_THRU_NINE:n {return($n)}
]

VSUB_DIGIT [
  [ zero oh ] {return(0)}
  VSUB_DIGIT_ONE_THRU_NINE:n {return($n)}
]

; Single-digit grammars that return string values

VSUB_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")}
]

VSUB_DIGIT_ONE_THRU_NINE_STRING [
  one {return("1")}
  VSUB_DIGIT_TWO_THRU_NINE_STRING:n {return($n)}
]

VSUB_DIGIT_STRING [
  [ zero oh ] {return("0")}
  VSUB_DIGIT_ONE_THRU_NINE_STRING:n {return($n)}
]

VSUB_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")}
]

VSUB_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")}
]

VSUB_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)}
]

VSUB_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)}
]