[math]\mathcal{A}(\mathbf{S}) = \{\alpha \in \mathcal{P}_1(\mathcal{P}_1(\mathbf{S})):\forall A_i,A_j \in \alpha, A_i \not \subset A_j\}[/math], | [math]\mathcal{A}(\mathbf{S}) = \{\alpha \in \mathcal{P}_1(\mathcal{P}_1(\mathbf{S})):\forall A_i,A_j \in \alpha, A_i \not \subset A_j\}[/math], |