prenex (Exists x p)  = let Prenex quantsp' p' = prenex p
                       in Prenex (QExists x:quantsp') p'
prenex (Exists x p)  = let Prenex quantsp' p' = prenex p
                       in Prenex (QExists x:quantsp') p'
prenex (Exists x p)  = let Prenex quantsp' p' = prenex p
                       in Prenex (QExists x:quantsp') p'