4.2. The boolean type

The boolean type is used for truthness values. It is extensively used in conditional constructs. The default value for the boolean type is falseness. The instance tom.All defines the following constants, each with the boolean type.

const TRUE = !0;
const FALSE = !1;
const YES = TRUE;
const NO = FALSE;

Therefore, any class which uses these constants must minimally inherit from instance tom.All or another class which does, such as State.