<font color='black' size='2' face='arial'><br> <span class="Apple-style-span" style="font-size: small; "><span class="Apple-style-span" style="font-size: small; ">Hello I have a program consists of two tasks. My first task works fine. In second task I have to create a new chip as soon as the new card has been created.</span> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">I am giving you sample run for the idea</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; "> <div>==> (define c1 (a-chip))</div> <div>c1</div> <div>==> (contents c1)</div> <div>0</div> <div>==> (charge c1 10.00)</div> <div>done</div> <div>==> (contents c1)</div> <div>10.0</div> <div>==> (discharge c1 9.34)</div> <div>9.34</div> <div>==> (contents c1)</div> <div>0.66</div> <div>==> (discharge c1 0.67)</div> <div>no</div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div> <div><br> </div> <div>==> (define alan (a-card 432776 1904))</div> <div>alan</div> <div>==> (define bill (a-card 1 95))</div> <div>bill</div> <div>==> (inserted bill 96)</div> <div>no</div> <div>==> (contents bill)                                        // HAVING PROBLEM IN THIS</div> <div>ERROR: Not inserted</div> <div>==> (inserted bill 95)</div> <div>done</div> <div>==> (contents bill)<span class="Apple-tab-span" style="white-space: pre; "> </span>//PROBLEM IN THIS</div> <div>0</div> <div>==> (free bill)</div> <div>done</div> <div>==> (new-pin bill 96)</div> <div>no</div> <div>==> (inserted bill 95)</div> <div>done</div> <div>==> (new-pin bill 96)</div> <div>done</div> <div>==> (account-number bill)</div> <div>1</div> <div>==> (free bill)</div> <div>done</div> <div>==> (account-number bill)</div> <div>1</div> </div> <div><br> </div> <div>I AM NOT ABLE TO WORK OUT CONTENTS IN TASK 2..</div> <div>I have already created contents in task 1. Do I have to create it again.</div> <div><br> </div> <div>let me summarise my problem- </div> <div>when I write (contents card) it has to work all the three procedures defined in task one contents, charge and discharge.</div> <div>I have given some efforts but don't worth it.</div> <div><br> </div> <div>Any help will be appreciated</div> <div>thanks</div> <div><br> </div> </span> <div><span class="Apple-style-span" style="font-size: small; ">;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;TASK 1;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">(define (a-chip)</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">  (let ( (balance 0) )</span></div> <div><span class="Apple-style-span" style="font-size: small; ">    (define (the-chip op)</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">(sequence</span></div> <div><span class="Apple-style-span" style="font-size: small; ">        (cond ((eq? op 'contents)     (lambda () balance))</span></div> <div><span class="Apple-style-span" style="font-size: small; ">              ((eq? op 'charge)         charge)</span></div> <div><span class="Apple-style-span" style="font-size: small; ">              ((eq? op 'discharge)      discharge)</span></div> <div><span class="Apple-style-span" style="font-size: small; ">              (else (error "chip: unknown operation" op))</span></div> <div><span class="Apple-style-span" style="font-size: small; ">        )</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">'nononon)</span></div> <div><span class="Apple-style-span" style="font-size: small; ">    )</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">    (define (charge amount)</span></div> <div><span class="Apple-style-span" style="font-size: small; ">        (set! balance amount)</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">'done</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span></div> <div><span class="Apple-style-span" style="font-size: small; ">    )</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">    (define (discharge amount)</span></div> <div><span class="Apple-style-span" style="font-size: small; ">       (if (> (- balance amount) 0)</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">( sequence (set! balance (- balance amount))</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">amount)</span></div> <div><span class="Apple-style-span" style="font-size: small; "> </span><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">'no</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">)</span></div> <div><span class="Apple-style-span" style="font-size: small; ">    )</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">    the-chip</span></div> <div><span class="Apple-style-span" style="font-size: small; ">  )</span></div> <div><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span><span class="Apple-style-span" style="font-size: small; ">"mjuu"</span><span class="Apple-tab-span" style="white-space: pre; "><span class="Apple-style-span" style="font-size: small; "> </span></span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">)</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">(define (charge chip amount)    ((chip 'charge) amount))</span></div> <div><span class="Apple-style-span" style="font-size: small; ">(define (discharge chip amount) ((chip 'discharge) amount))</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; ">(define (contents chip) ((chip 'contents) ))</span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; "><br> </span></div> <div><span class="Apple-style-span" style="font-size: small; "> <div>;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;TASK 2;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;</div> <div><br> </div> <div><br> </div> <div>(define (a-card account tpin)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>( let ( (chip #f))</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>   (define (the-card request)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>(cond ((eq? request 'inserted)<span class="Apple-tab-span" style="white-space: pre; "> </span>inserted)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>      ((eq? request 'free)<span class="Apple-tab-span" style="white-space: pre; "> </span>  free)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>      ((eq? request 'new-pin)<span class="Apple-tab-span" style="white-space: pre; "> </span>new-pin)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>      ((eq? request 'account)<span class="Apple-tab-span" style="white-space: pre; "> </span>( lambda () account))</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span><span class="Apple-tab-span" style="white-space: pre; "> </span>      (else (error "card: unknown operation" request))</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>)</div> <div>)</div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div>(define (inserted pin )</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>(if (= pin tpin)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>(sequence (set! chip #t)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span></div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span></div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span></div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>'done)<span class="Apple-tab-span" style="white-space: pre; "> </span></div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>'no))</div> <div><br> </div> <div>(define (free)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>(sequence (set! chip #f)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>'done)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>)</div> <div><br> </div> <div><br> </div> <div>(define (new-pin new)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>(if (eq? #t chip )</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>(sequence (set! tpin new )</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>'done)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>'no)</div> <div>)</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span></div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span></div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><br> </div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>the-card</div> <div><span class="Apple-tab-span" style="white-space: pre; "> </span>)</div> <div>   )</div> <div><br> </div> <div><br> </div> <div>(define (contents card)<span class="Apple-tab-span" style="white-space: pre; "> </span>((card 'contents)))</div> <div>(define (pupu card)<span class="Apple-tab-span" style="white-space: pre; "> </span>((card 'pupu)))</div> <div>(define (inserted card pin)<span class="Apple-tab-span" style="white-space: pre; "> </span>((card 'inserted ) pin))</div> <div>(define (free card)<span class="Apple-tab-span" style="white-space: pre; "> </span>((card 'free)))</div> <div>(define (new-pin card new)<span class="Apple-tab-span" style="white-space: pre; "> </span>((card 'new-pin) new))</div> <div>(define (account-number card)<span class="Apple-tab-span" style="white-space: pre; "> </span>((card 'account)))</div> <div><br> </div> </span></div> </div> </span> <div style="clear:both"></div> </font>