Boolean domain

genericGeneric

A Boolean domain $𝔹$ is a generic 2-element set, say, $𝔹=\{0,1\}$, whose elements are interpreted as logical values, typically, $0=\mathrm{false}$ and $1=\mathrm{true}$.

A Boolean variable $x$ is a variable that takes its value from a Boolean domain, as $x\in 𝔹$.