; apply-binary-operator
;
; input to the function: 
;  the name of a binary boolean operator
;    a list of Ls and Hs
;  two bolean values
;    one variable that's either L or H
;    a second variable that's either L or H
; output
;  the result of applying the operator to the values
;
; examples
;   (apply-binary-operator '(L L L H) 'H 'L) -> 'L
;   (apply-binary-operator '(L H H H) 'L 'H) -> 'H
;

(define (apply-binary-operator operator-name first-input second-input)
  (if (eq? first-input 'L)
      (if (eq? second-input 'L)
          (list-ref operator-name 0)
          (list-ref operator-name 1))
      (if (eq? second-input 'L)
          (list-ref operator-name 2)
          (list-ref operator-name 3))))

(define (make-binary-operator operator-name)
  (lambda (first-input second-input)
    (apply-binary-operator operator-name first-input second-input)))

(define (select-first-or-second input-list value)
  (if (eq? value 'H) 
      (list-ref input-list 1)
      (list-ref input-list 0)))

(define (eval-nested-binary nested-operator v1 v2)
  (select-first-or-second
   (select-first-or-second nested-operator v1)
   v2))