PERCENT_GRAM 
[
VLIB_PERCENTAGE:z {<MyField1 $z>}
]

VLIB_PERCENTAGE  [
	VSUB_PERCENTAGE:x
] { return (strcat("" $x)) }

VSUB_PERCENTAGE [
  ( [ half {return(50)}
      ( a third ) {return(33)}
      ( two thirds ) {return(67)}
      ( a quarter ) {return(25)}
      ( three quarters ) {return(75)}
 
    ]
    ?( of it )
  )
  [ ( none of it ) 
    ( [ none nothing ] ?( at all ) )
  ] {return(0)}
  [ ( all ?( of it ) ) 
    ( the whole thing )
    everything
  ] {return(100)}
  ( [ VSUB_DIGIT:n {return($n)}
      VSUB_TEEN:t {return($t)}
      VSUB_DECADE:n {return($n)}
      ( VSUB_DECADE:t VSUB_DIGIT_ONE_THRU_NINE:u ) {return(add($t $u))}
      ( [ a one ] hundred ) {return(100)}
    ]
    ?( percent ?( of it ) )
  )
]


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 [
  ten {return(10)}
  twenty {return(20)}
  thirty {return(30)}
  forty {return(40)}
  fifty {return(50)}
  sixty {return(60)}
  seventy {return(70)}
  eighty {return(80)}
  ninety {return(90)}
]