Identifier	= Letter { Letter | Digit } .
Literal		= "\"" { Letter | Digit } "\"".
Integer		= Digit { Digit }.
Letter		= "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z".
Digit		= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9".