event
  /* 
   * les priorites dependent des actions sur la vanne aval
   * inc > nop > dec
   */
  {ddi, dii, dni, idi, iii, ini, ndi, nii, nni} >
    {ddn, din, dnn, idn, iin, inn, ndn, nin, nnn};
  {ddn, din, dnn, idn, iin, inn, ndn, nin, nnn} >
    {ddd, did, dnd, idd, iid, ind, ndd, nid, nnd};
edon