I have the following function definition :

let myfun param=
   let res=Marshal.from_channel stdin [] in
     if res=param then
       res
     else res
;;

Since the type of "Pervasives.=" is "'a -> 'a -> bool",
I was expecting :

myfun : 'a -> 'a

I got instead :

myfun : 'a -> 'b

Is it normal ?