 \(\langle a, b \rangle \in \bOmega^{\sim}_{\bA }(\cB)\txtiff\) for every \(\phi(p, q_1 , \ldots ,q_n)\) and every \(c_1 , \ldots ,c_n \in A, C_{\cB }(\phi^{\bA }[a, c_1 , \ldots ,c_n]) = C_{\cB }(\phi^{\bA }[b, c_1 , \ldots ,c_n])\).