Exercise 3.58: Give an interpretation of the
stream computed by the following procedure:


(define (expand num den radix)
  (cons-stream
   (quotient (* num radix) den)
   (expand (remainder (* num radix) den) 
           den 
           radix)))

(Quotient is a primitive that returns the integer quotient of two
integers.)  What are the successive elements produced by (expand 1 7
10)?  What is produced by (expand 3 8 10)?