impc:ti:type-clean   scheme

(define impc:ti:type-clean
  (lambda (type)
    (if (or (null? type)
            (atom? type)
            (impc:ir:type? type)) ;; (note to andrew) remove this line for GC crash!
        type
        (map (lambda (k)
               (if (list? k)
                   (if (= (length k) 1)
                       (impc:ti:type-clean (car k))
                       (impc:ti:type-clean k))
                   k))
             type))))