Yet Another Drawing Machine
When a system is subject to a particular disturbance, it can see its set-up change. If at the end of the perturbation the system returns to its initial condition, the system is called stable. When, on the contrary, it definitively moves away from the initial conditions, it is called an unstable system. YADM is a fragile system, composed of heterogeneous elements that inexorably record the influence on them of a force as invisible as real, the wind.