; A group tester
; this version uses Scheme’s equal? for equality for speed and
; distrust of z?, -g.
; This presumes categorical and non abstracted group values.
; Thing negative: "Did you find a violation?".
(lambda (g s m n) (apply (lambda (z +g -g G z?)
  (if (z? G) "G is zero" (if (not (z? z)) "z is not zero"
  (let ((ran ((((fileVal "RC4") s) 'rbi) m))
        (sp ((fileVal "expt") +g z -g)))
  (let ((gi (lambda () (sp G (ran)))))
    (let y ((n n)) (or (zero? n)
    (let* ((a (gi)) (b (gi)) (c (gi))
    (ne (lambda (x y) (or (equal? x y) (list a b c)))))
    (and (ne (+g a b) (+g b a))
   (ne (+g a (+g b c)) (+g (+g a b) c))
   (ne (+g (+g a b) (-g b)) a) (y (- n 1))))))))))) g))

((fileVal "crypto/GT") ((fileVal "crypto/MI") 641) "Flos" 53 200)
((fileVal "crypto/GT") ((fileVal "crypto/MI") 640) "lug" 1000 2000)