 Metatheorem: Let \(\psi\) be a formula of \(\scrL_\Box\) that contains an individual constant \(\kappa\) of \(\scrL_\Box\) and let \(\nu\) be a variable that doesn’t occur in \(\psi\). Then if \(\psi\) is a theorem of SQML, so is  \(\forall\nu\psi^\kappa_\nu.\)[42]