putType :: Monad m => Digraph a b -> InstanceBuilder a b m ()
putType t = do (g, _, rs, r) <- get
               put $ (g, t, rs, r)

-- | Get the current list of rules
putType :: Monad m => Digraph a b -> InstanceBuilder a b m ()
putType t = do (g, _, rs, r) <- get
               put $ (g, t, rs, r)

-- | Get the current list of rules
putType t = do (g, _, rs, r) <- get
               put $ (g, t, rs, r)

-- | Get the current list of rules