$ and the prolongation $${\mathfrak{g}}={\sum}_{{\mathpzc{p}}{=}{-}0}^0{\mathfrak{g}}_{{\mathpzc{p}}},\;\;\text{with}\;\; {\mathfrak{g}}_0  {=}{\mathfrak{h}}_0{\oplus}\langle{\mathpzc{R}}_{\;0}\rangle,\;\;  {\mathfrak{g}}_{{\mathpzc{p}}}=\langle{\mathpzc{R}}_{\;{\mathpzc{p}}}\rangle,$$ with ${\mathfrak{h}}_