 Recursive: For all assignments \(a\), sentences \(\phi, \psi\), and truth-functional connectives \(@\), \(\cq{\phi @ \psi }\) is satisfied by \(a\) iff Ref(\(@, a\))(Val(\(\phi, a\)), Val(\(\psi,a\))) = True (where Val(\(\phi, a\)) = True if \(\phi\) is satisfied by \(a\), False if \(\phi\) is not satisfied by \(a\)). (cf. Evans 1976, 214)