anchor.diff:        (single body)
           (car body)
         `(let1 it ,(car body)
  +	(declare (ignorable it))
           (ado ,@(cdr body)))))
   
   (mac accum (accfn &body body)
  
positive.code: 	`(let1 ,gv ,expr
  	   (lf ,gv
  	       (let1 ,var ,gv
  		 ,(car branches))
  	       ,(lf (cdr branches)
  		    `(lflet ,var ,@(cdr branches))))))
  
negative.code: (def keys (tab)
    "Evaluates to all of the keys in the hash table tab"
    (ret result '()
      (maphash (fn (k v)
  		 (declare (ignore v))
  		 (push k result))
  	     tab)))
  
  (def vals (tab)
    "Evaluatates to all of the values in the table tab"
    (ret result '()
      (maphash (fn (k v)
  		 (declare (ignore k))
  		 (push v result))
  	     tab)))
  
  (def listtab (xs)
    "Evaluates to a table which is equivalent to the alist xs"
  