racket shitty code that works

#lang racket
(define (sicher? str f g h)
  (rec str #f #f #f f g h 0)
)
(define (rec str fdone gdone hdone f g h k)
(if (and fdone gdone hdone)
    #t
  (if (= k (string-length str))
      #f
      (rec str
        (or fdone (f (string-ref str k)))
        (or gdone (g (string-ref str k)))
        (or hdone (h (string-ref str k)))
        f g h (+ k 1)
        )
   )
)
)