Boolean

In formal logic, a boolean variable is a variable that can take on one of only two possible values: “true” or “false”. Propositions can then be said to evaluate to one of these two values, in the same way that ordinary algebraic expressions evaluate to a number.

Also as in algebraic expressions, boolean values can be manipulated using certain operators such as \(\land\) (and), \(\lor\) (or), \(\neg\) ([negation), and \(\rightarrow\) (implication). This field is called, surprisingly, boolean algebra.

Because booleans can only express absolute truth or falsity, when working with measures of uncertainty you must use other representations, such as probability.