Definition:Fiber of Truth

Let $$\mathbb{B} = \left\{{T, F}\right\}$$ be a boolean domain.

Let $$f : X \to \mathbb{B}$$ be a boolean-valued function.

The fiber of truth (under $$f$$) is the fiber or preimage of $$T$$ and can be denoted $$ \left[\left|{f}\right|\right]$$:


 * $$ \left[\left|{f}\right|\right] = \left\{{x \in X: f \left({x}\right) = T}\right\}$$