👉 Presmooth is a mathematical concept in optimization and control theory that refers to a continuous function f(x) whose derivative at every point x = 0 is zero. This means that f is non-differentiable at x = 0, but its graph contains only points where the gradient is zero. In other words, if f is a continuous function defined on an interval [a, b] and differentiability is assumed for some values of x in this interval, then it is possible to define
