i do not use any type applications, but for convienience i implement some prelude function such as catMaybeS and so on. is that affect?

Failed to parse solution for "do not use implemented Prelude" test, got messsage:

uncaught exception: IOException of type UserError
user error (Could not parse solution correctly)

But I really cannot findout which function in my code is the 'implemented Prelude', can we provide more specific limits?

besides, here is the Prelude functions I used:

(,), Just, Nothing, (:), ([]), Left, Right