gistfile1.scm

(require srfi/1)

(define || (lambda (x y) (or x y)))
(define && (lambda (x y) (and x y)))
(define --> 
  (lambda (x y) 
    (not (and x (not y)))))

(define interpret
  (lambda (f)
    (list-of (list (f x y z) (list x y z)) 
             (x <- '(#t #f))
             (y <- '(#t #f))
             (z <- '(#t #f)))))

(define helper
  (lambda (m s f)
    (list-of (m n)
             (n <- (filter s (interpret f))))))

(define valid?
  (lambda (f)
    (every 
     (lambda (x) x)
     (helper car (lambda (x) #t) f))))

(define models
  (lambda (f)
    (helper cadr (lambda (x) (car x)))))