Free tradeFree trade is a trade policy that does not restrict imports or exports. In government, free trade is predominantly advocated by political parties that hold economically liberal positions, while economic nationalist and left-wing political parties generally support protectionism, the opposite of free trade. Most nations are today members of the World Trade Organization multilateral trade agreements. Free trade was best exemplified by the unilateral stance of Great Britain who reduced regulations and duties on imports and exports from the mid-nineteenth century to the 1920s.
Convex setIn geometry, a subset of a Euclidean space, or more generally an affine space over the reals, is convex if, given any two points in the subset, the subset contains the whole line segment that joins them. Equivalently, a convex set or a convex region is a subset that intersects every line into a single line segment (possibly empty). For example, a solid cube is a convex set, but anything that is hollow or has an indent, for example, a crescent shape, is not convex. The boundary of a convex set is always a convex curve.
No-communication theoremIn physics, the no-communication theorem or no-signaling principle is a no-go theorem from quantum information theory which states that, during measurement of an entangled quantum state, it is not possible for one observer, by making a measurement of a subsystem of the total state, to communicate information to another observer. The theorem is important because, in quantum mechanics, quantum entanglement is an effect by which certain widely separated events can be correlated in ways that, at first glance, suggest the possibility of communication faster-than-light.
