A grammar whose properties can be overridden.
See also
Adaptive grammar at the Wikipedia.
An operand whose value is used explicitly in a boolean expression. In Booleano, it can be an string, a number or a set.
See also
Literal at the Wikipedia.
The literal representation of an string.
In the default grammar, strings are delimited by single or double quotes, so the string Hello world can be written as:
See also
String literals at the Wikipedia.