I need to read 2 lists to get the difference set to get a third list, where A contains what B = C does not have

Question

i have this code

dif::[Int]->[Int]->[Int]
dif [] [] = []
dif (lista) (l:ls) = fun2 lista l

fun2::[Int]->Int->[Int]
fun2 [] p = []
fun2 (x:y:zs) p = i