A Feature Map Makes XOR Linear
Key concept: Adding the nonlinear feature x₁x₂ lifts XOR into 3D, where a plane separates all four points.
A line separates at most 3/4 XOR corners in 2D. Press Lift to add x₁x₂, then drag the 3D view: a plane now separates 4/4, while the 2D boundary becomes a cross.
What to look for: one new coordinate makes the points separable by a flat boundary.
Open the demo in a new tab for more room.