newRule :: Monad m => InstanceBuilder a b m Int
newRule = do rs <- getRules
             let newId = length rs
             putRules $ (newId, Morphism [] []):rs
             return $ newId

-- | Deletes the selected rule.
newRule :: Monad m => InstanceBuilder a b m Int
newRule = do rs <- getRules
             let newId = length rs
             putRules $ (newId, Morphism [] []):rs
             return $ newId

-- | Deletes the selected rule.
newRule = do rs <- getRules
             let newId = length rs
             putRules $ (newId, Morphism [] []):rs
             return $ newId

-- | Deletes the selected rule.