This paper investigates a first-order extension of GL called \(\textup{ML}^3\). We outline briefly the history that led to \(\textup{ML}^3\), its key properties and some toolbox: \emph{conservation theorem}, cut-free Gentzenisation, ``formulators'' tool. Its semantic completeness (with respect finite reverse well-founded Kripke models) is fully stated in current proof retold here. Applying Solo...