“…They are frequently treated by ad hoc modifications of tools borrowed from smooth systems; reviews can be found in [12,70,74,99]. A few of the wide range of applications that exhibit piecewise smooth dynamics include mechanical problems of friction [43,82,35,96,68,56], switched feedback in control theory [97,61,39,28] and electronics [22,5,9,79,32], nonsmooth models in economics [62,50], ecology [69,38,40], neuron signaling [33,34,76], genetic potentials [53,36,21,54], and novel nonlinear effects of superconductors [8,63]. Interest in such diverse applications in the vacuum of an insufficiently developed theory has left behind a nomenclature that is dogged by semantic difficulties.…”