{- | uniquely rename variables in quantified formulas and always
     quantify only over a single variable -}
convertFormula :: Int -> (f -> f) -> FORMULA f -> FORMULA f
convertFormula n = foldFormula . convertRecord n
convertFormula :: Int -> (f -> f) -> FORMULA f -> FORMULA f
convertFormula n = foldFormula . convertRecord n
convertFormula n = foldFormula . convertRecord n