The split-complex line is a space created from considering all points that can be labeled with one split-complex number, numbers similar to complex numbers but the imaginary unit is a solution to the square root of +1 rather than -1. This gives it one split-complex dimension, and two real dimensions.
The split-complex line is isomorphic to the real plane and multiplication of split-complex numbers on the unit hyperbola can represent Lorentz transformations of a Minkowski plane akin to how the complex line is isomorphic to the real plane and multiplication of complex numbers on the unit circle can represent rotations of the Euclidean plane.