Create the three types of smoothstep function out of given limits.

Input parameters:

1. X0 → Transition from constant values to smoothstep curve.
2. X1 → Transition from constant values to smoothstep curve.
3. Y0 → Elevation at first transition.
4. Y1 → Elevation at second transition.

Output parameters:

1. S3 → Smoothstep function with degree 3 on the given limits.
2. S5 → Smootherstep function with degree 5 on the given limits.
3. S7 → Smootheststep function with degree 7 on the given limits.