“…In recent years there has been an increasing interest in the geometric treatment of nonholonomic mechanical systems, see, e.g., [2,3,5,6,10,12,19,28,29,31,[38][39][40]. In particular, it has been recognised that the Hamiltonian formulation of such systems can be stated in terms of an almost-Poisson bracket, that is, a biderivation of functions of phase space, antisymmetric in its arguments but which does not necessarily fulfil the Jacobi identity (see, e.g., [1,11,36]).…”