sicp-ex-4.40

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