 The Belnap matrix \(\mathbf{B}_4\) considered above also can be represented as a partially ordered valuation system. The set of truth values \(\{\mathbf{N}, \mathbf{T}, \mathbf{F}, \mathbf{B}\}\) from \(\mathbf{B}_4\) constitutes a specific algebraic structure – the bilattice FOUR\(_2\) presented in Figure 3 (see, e.g., Ginsberg 1988, Arieli and Avron 1996, Fitting 2006).