anchor.diff:      (loop
         (fresh-line)
         (format t "LISP> ")
  -;;      (t-print (t-eval (read) env))
  -      (handler-case
  -      	  (t-print (t-eval (read) env))
  -      	(error (e) (princ e))))))
  +      (t-print (t-eval (read) env))
  +      ;; (handler-case
  +      ;; 	  (t-print (t-eval (read) env))
  +      ;; 	(error (e) (princ e))))))
         )))
  
positive.code: 	     (if (null clauses)
  		 'false
  		 (let* ((clause (first-cond-clause clauses))
  			(pred (cond-clause-pred clause))
  			(exps (cond-clause-exps clause)))
  		   (if (eq pred 'else)
  		       `(begin ,@exps)
  		       `(if ,pred
  			    (begin ,@exps)
  			    ,(iter (rest-cond-clauses clauses))))))))
      (iter (cdr exp))))
  
  ;; (cond (pred1 exp1 ...)
  
negative.code: (defun rest-cond-clauses (exp)
    (cdr exp))
  
  (defun cond-clause-recipient-p (exp)
    (eq (cadr exp) '=>))
  
  (defun cond-clause-pred (clause)
    (car clause))
  
  (defun cond-clause-exps (clause)
    (cdr clause))
  
  (defun cond-clause-recipient (clause)
    (caddr clause))
  
  (defun else-clause-p (clause)
    (tagged-list-p clause 'else))
  