well let's talk more about the divorce still in the conundrum facing theresa may we have derek scally with us correspondent for the irish times newspaper here in berlin derek good morning to you thank you for joining us we've seen one of the biggest obstacles to the deal by both the e.u. and the u.k. on both sides has been the question of the border between the republic of ireland and northern ireland remind us what the backstop is and why this is been such a sticking point in the backs of is effectively and it's an insurance policy twenty years ago we had a peace agreement in the agreement was yes there is a sovereign border there but if we will keep it open we will keep it open for the thirty thousand people who commute back and forth to keep it open for the traders so that effectively we have one trading regime but of course of britain wants to leave the e.u. the free market and. this is going to cause. tremendous problem for traders for people who you're dealing with two different regimes and when you have two different regimes you've borders when you have borders you've queues and you've