“…The Pontryagin Maximum Principle can be generalized to wider classes of functionals and boundary conditions; for instance, periodic boundary conditions (see [17]), systems involving some delays (see [14,26]), intermediate conditions (see [9,27,28]), or, more generally, hybrid systems where the dynamics may change along the trajectory, accordingly to time and/or state conditions (see [29,30,31,32,33,21]). In particular in this last case, when the system crosses a given boundary then a jump condition must hold on the adjoint vector, which means that the adjoint vector is no more continuous (but is however piecewise absolutely continuous).…”