  where \(A\) is an axiom of \(\mathcal{L}\), and  \(e_{1} , e_{2}, \ldots, e_{n}\) are similar constants with indices 1, 2, …, \(n\). It is assumed that \(CS\) contains all  intermediate specifications, i.e., whenever  \(e_{n} : e_{n- 1}:\ldots:e_{1} : A\) is in \(CS\), then  \(e_{n- 1}:\ldots:e_{1} : A\) is in \(CS\) too.