rational surface
英[ˈræʃənl ˈsə:fis]美[ˈræʃənəl ˈsɚfəs]
In algebraic geometry, a branch of mathematics, a rational surface is a surface birationally equivalent to the projective plane, or in other words a rational variety of dimension two. Rational surfaces are the simplest of the 10 or so classes of surface in the Enriques-Kodaira classification of complex surfaces,