(define (require p)
(if (not p) (amb)))

(define (distinct? items)
    (cond ((null? items) true)
          ((null? (cdr items)) true)
          ((member (car items) (cdr items)) false)
          (else (distinct? (cdr items)))))

(define (multiple-dwelling)
  (let  ((baker  (amb 1 2 3 4 5))
         (cooper (amb 1 2 3 4 5))
         (fletcher  (amb 1 2 3 4 5))
         (miller (amb 1 2 3 4 5))
         (smith  (amb 1 2 3 4 5))
      (require
       (distinct? (list baker cooper fletcher miller smith)))
(require (not (= baker 5)))
(require (not (= cooper 1)))
(require (not (= fletcher 5)))
(require (not (= fletcher 1)))
(require (> miller cooper)))
(require (not (= (abs (- smith fletch)) 1)))
(require (not (= (abs (- fletcher cooper)) 1)))
(list (list 'baker baker)
      (list 'cooper cooper)
      (list 'fletcher fletcher)
      (list 'miller miller)
      (list 'smith smith))))