Cover V11, I01

Article
Figure 1

jan2002.tar

Figure 1 Example output

(define bankobject (create-piggybank))
((bankobject 'deposit) 50)
((bankobject 'print_balance))
;Value: 50
(define (bankobject2 (create-piggybank))
((bankobject 'print_balance))
;Value: 0