Reference: animateTrajectory

animateTrajectory(S, I, b) animates the particle or flow trajectory set S, created using computeParticleTrajectory or computeFlowTrajectory. S is required to be a subset of R^2. I is the number of steps in time per frame. If b=true, the particle's trace is shown on the screen.

Example: Bouncing ball in gravity in a 2D box
         trajectory ≔ computeParticleTrajectory("❨0, -1❩", "r", ❨-10, 10❩, ❨1, 0❩, 0, 100, 0.01, ❨-10, 10, -10, 10❩, 0.8)
         animateTrajectory("trajectory", 30, true)