As a single production base and market (single market and production base) by the movement of goods. Services, investment and skilled labor and capital movements are more liberal.
A single market and production base (single market and production base), with the movement of goods, services, investment and skilled workers freely. And capital flows more freely.
A single market and production base (single market and production base) the flows of goods, services, investment and skilled workers freely. And the free flow of capital.