/-  hood
:-  %say
|=  $:  [now=@da eny=@uvJ bec=beak]
        $:  =desk
            arg=(list [? dude:gall])
        ==
        liv=_&
    ==
:-  %kiln-rein
:-  desk
%+  roll  arg
=/  =rein:hood
  =<  rein.arak
  .^(vat:hood %gx /(scot %p p.bec)/hood/(scot %da now)/kiln/vat/[desk]/noun)
|:  [*[on=? =dude:gall] rein=rein(liv liv)]
?:  on
  rein(add (~(put in add.rein) dude))
rein(sub (~(put in sub.rein) dude))