Definition:Singular Boolean Function

Definition
A singular boolean function $s : \mathbb B^k \to \mathbb B$ is a boolean function whose fiber of truth is a single element of $\mathbb B^k$.

Where the boolean domain $\mathbb B = \left\{{T, F}\right\}$ is given a logical interpretation, a singular boolean function is called a singular proposition.

That is, a singular proposition $P$ is one in which there exists only one model $\mathcal M \models P$.