additive discrete animation
A circle jumps from left to center and back using one
additive discrete animation with a duration of 8s and
a begin list with 0s (light gray path) and 2s (gray path).
The gray animation overwrites the light gray one,
independent of the additive attribute.
A linear move in y direction corresponding to the time
and paths are given for comparison.
If the red center of the circle gets visible, an error occured.