; this returns EPR pairs.
(let ((pi (* 4 (atan 1))) (sq (lambda (x) (* x x))))
  (lambda (seed) (let ((bc ((fileVal "bCoin") seed)) (U (((fileVal "RC4") seed) 'U)))
  (lambda () (let* ((th #f) (x (lambda (theta) (if th
        (bc (sq (cos (- th theta))))
        (if (bc 0.5) (begin (set! th theta) #t)
              (begin (set! th (+ (/ pi 2) theta)) #f))))))
      (cons x x))))))

; tests:
(define ppg ((fileVal "EPR") "glosh"))
; (define ex (lambda (m v) (write (list m v)) (newline) v))
(define U (((fileVal "RC4") "BiLge") 'U))
(define pi (* 4 (atan 1)))
(define (t da) (let* ((H (make-vector 4 0)))
   (((fileVal "Do") 'Do) 10000
     (lambda (_) (let* ((pp (ppg))(x (car pp))(y (cdr pp)) (th (* pi (U)))
        (n (+ (if (x th) 1 0) (if (y (+ th da)) 2 0))))
    (vector-set! H n (+ 1 (vector-ref H n)))))) H))
(list (t 0) (t (/ pi 2)) (t (/ pi 4)))
; => (#4(4949 0 0 5051) #4(0 5076 4924 0) #4(2421 2501 2535 2543))