toTseitinEncode (And e1 e2) =
    let a1 = newRef [1]
        a2 = newRef [2]
        in foldAnd ([And a1 a2] ++ (toTseitinEncode' [1] e1) ++ (toTseitinEncode' [2] e2))
toTseitinEncode (And e1 e2) =
    let a1 = newRef [1]
        a2 = newRef [2]
        in foldAnd ([And a1 a2] ++ (toTseitinEncode' [1] e1) ++ (toTseitinEncode' [2] e2))
toTseitinEncode (And e1 e2) =
    let a1 = newRef [1]
        a2 = newRef [2]
        in foldAnd ([And a1 a2] ++ (toTseitinEncode' [1] e1) ++ (toTseitinEncode' [2] e2))