sicp-ex-5.23

  
  
  
 ;;  add those following ev-dispatch 
 (test (op cond?) (reg expr)) 
 (branch (label ev-cond)) 
  
  ev-cond 
  (assign expr (op cond->if) (reg expr)) 
 (goto (label ev-if)) 
  
 ;; add those to eceval-operations 
  (list 'cond? cond?) 
 (list 'cond->if cond->if)