Point at infinity complex field, the set of points at infinity is a manifold. In artistic drawing and technical perspective, the projection on the picture plane of the point at infinity of a class of parallel lines is called their vanishing point. In hyperbolic geometry, points at infinity are typically named ideal points. Unlike Euclidean and elliptic geometries, each line has two points at infinity: given a line "l" and a point "P" not on "l", the right- and left-limiting parallels converge asymptotically to different points at infinity. All points at infinity together form the Cayley absolute or boundary of a hyperbolic plane.
Point-to-point transit Point-to-point transit Point-to-point transit refers to a transportation system in which a plane, bus, or train travels directly to a destination, rather than going through a central hub. This differs from the spoke-hub distribution paradigm in which the transportation goes to a central location where passengers change to another train, bus, or plane to reach their destination. The point-to-point model is used widely by low cost carriers, including Allegiant Air and Southwest Airlines in the U.S., and European carriers such as Ryanair, easyJet and Wizzair. Many such airlines sell each flight leg independently and have no concept of round-trip ticketing