The status of each of these islands' component parts is in question like never before as a result of the Brexit vote. Professor Brendan O'Leary proposes a novel solution - continuing membership of both the EU and the UK for Northern Ireland and Scotland, with Wales and England out of the former. But how could it work and what problems would need to be surmounted?And what would it mean for us? To answer those questions, Professor O'Leary joins Irish Times News Editor Mark Hennessy.