Create a recursive function FILTERTYPE that takes a type name (see #4) and a list. It should return the list with all items of that type removed. Do error checking on the input.

[67]>  (filtertype 'number '(a 2 (3 4) b)) (a (3 4) b) [72]> (filtertype 'nil '(a () (b c) nil)) (a (b c)) [73]> (filtertype 'blah '(a b c)) Error in FILTERTYPE function. First argument must be a valid type name.