System.False - Manhunter07/MFL GitHub Wiki
Declaration
const False = \built-in\
Description
The False constant in the System package represents the False-value of a boolean expression. It invokes the then-branch when used in a conditional context (ie. in an if statement). This does not mean however that falsy values are limited to exactly this, but it is the one supported by the Boolean type.
System.False is the logical opposit of System.True. Thus, negating one will result in the other.