In this demo, you can see different slices of the graph of a function f(x,y,z). In the 4D Color Graph window, you again see the color graph of the function f(x,y,z). In the Color Slice window, you can see an arbitrary plane slicing the color graph, and this slice is again shown in the Slice Surface window: The z-coordinate here is determined by the function value f(x,y,z₀(x,y)).