newCondTrans :: Monad m => PNExpr -> [PlaceNo] -> [PlaceNo] -> [PNExpr] ->
        MkPNMonad m value TransNo
    newCondTrans cond inPlaces outPlaces exprs = do
        label <- getLabel
        addTrans $ Trans label inPlaces outPlaces (Just cond) exprs $ const $ return ()
newCondTrans :: Monad m => PNExpr -> [PlaceNo] -> [PlaceNo] -> [PNExpr] ->
        MkPNMonad m value TransNo
newCondTrans cond inPlaces outPlaces exprs = do
        label <- getLabel
        addTrans $ Trans label inPlaces outPlaces (Just cond) exprs $ const $ return ()
newCondTrans cond inPlaces outPlaces exprs = do
        label <- getLabel
        addTrans $ Trans label inPlaces outPlaces (Just cond) exprs $ const $ return ()