(de mnorm (Email)
  (let (c (chop Email) Email ())
     (while (or (unless c  (rollback) (throw 'parse "no @")) (<> "@" (car c)))   ## processing local part
       (when (= (car c) "\\") (do 2 (push 'Email (pop 'c))))
       (when (= (car c) "(")
         (while (or (unless c  (rollback) (throw 'parse "unmatched paran")) (<> (car c) ")" ) )
           (pop 'c)
         )
         (pop 'c)
       )
       (when (= (car c) "\"")
          (push 'Email (pop 'c))
          (while (<> "\"" (car c))
            (push 'Email (pop 'c))
          )
       )
       (if (= "+" (car c))
          (while (<> "@" (car c))
            (pop 'c)
          )
          (push 'Email (pop 'c))
       )
     )
  (when (=0 (length Email)) (rollback) (throw 'parse "no local part"))
  (when (=0 (dec (length c))) (rollback) (throw 'parse "no host part"))
  (pack (reverse Email)   c)
  )
)

(class +MInd)
(dm has> (Val X)
   (extra Val
      (if (= Val (mnorm Val)) (mnorm X) X) ) )

(dm rel> (Obj Old New Hook)
   (extra Obj (mnorm Old) (mnorm New) Hook) )

(dm rel?> (Obj Val Hook)
   (let V (mnorm Val)
      (or (not V) (extra Obj V Hook)) ) )

(dm lose> (Obj Val Hook)
   (extra Obj (mnorm Val) Hook) )

(dm keep> (Obj Val Hook)
   (extra Obj (mnorm Val) Hook) )