从戴高乐机场坐RER到巴黎市区转地铁，还用重新

从戴高乐机场坐RER到巴黎市区转地铁，还用重新买地铁票吗？

我在ParisByTrain.com的网站上看到在介绍从戴高乐到时中心交通时，有这样的一段话

“ Finally, your RER train ticket is also good for connections onto the Paris Metro and other RER train lines once you’ve arrived in Paris; There’s no need to purchase a separate Paris Metro/RER Ticket T+ for making connections within the city centre onto other Metro or RER trains (but not buses nor trams, which require a new ticket).”


这个意思是在市区不用重新买地铁票，直接用RER的票就可以在市区坐地铁了。。实际情况是这样吗？