No copying from others or ill report

9. Describe in detail what the type means, including how its components are related from the definition of following function "foo in SML. (10 points). Write an example code of your own function foo which has the same type definition. Then, test your function foo by feeding sample input and write expected output (result). Briefly explain your code and experiment to get any credit. (10 points). foo: ('a -> bool) -> 'a list -> 'a list