  Finally, the Constant Specification \(CS\) should be taken into  account. Recall that constants are intended to represent reasons for  basic assumptions that are accepted outright. A model  \(\mathcal{M} = \langle \mathcal{G} , \mathcal{R} , \mathcal{E} , \mathcal{V}\rangle\)   meets Constant Specification \(CS\) provided: if  \(c : X \in CS\) then  \(\mathcal{E}\)(c,X) = \(\mathcal{G}\).