Declarations

DXL has the following 'base types':
 * bool : Boolean. The values true or false which are predefined constants
 * char : Character. Single-byte character, e.g. 'a'
 * int : Integers in the range -2,147,483,648 to +2,147,483,647
 * real : 64bit precision, e.g. 3.141592654
 * void : No values allowed. Its main use is to declare functions that return no value.
 * string : A string of more than one character, e.g. "I am a string"