Seriously though, obviously its impossible for May because of all the red lines she drew, but I think if your starting point is that you want Brexit but you don't want to control the flow of goods, services and labour over borders then it's less of a problem. Tory Brexit obviously means immigration control, but I don't think leaving the EU has to mean that. A starting point could be that you say free movement of labour continues but we won't accept the Posted Workers directive, for example. Although this is all irrelevant now as our Neoliberal Overlords have very nearly worked out how to keep us in the EU.