'Returns the right hand side of the equations of motion in explicit
form, x\' = F, where the kinematical equations are included'

@property
def comb_explicit_rhs(self):

    if (self._comb_explicit_rhs is None):
        raise AttributeError('Please    run    .combute_explicit_form    before    attempting    to    access    comb_explicit_rhs.')
    else:
        return self._comb_explicit_rhs
