Use structural induction to prove the following proposition: All formulas of the form where each Fi is a satisfiable formula is itself satisfiable. For this problem the satisfiable formulas Fi play the role of atoms. Hence the base case for structural induction must be modified accordingly. $($To clarify, all parent nodes are V $($OR$),$ there is a dotted line where there appears to be no connection, and the bottom children are Fn$-1$ and Fn$.$ Apologies for the poor image quality.$)$