E + P <-> E_P_1 E_P_1 -> E + M M -> M1 E + M1 <-> E_M1 E + M <-> E_M E_M1 -> E + T E_M -> E + T E + P <-> E_P_2 E_P_2 -> E + P2 P2 -> P21 E + P21 <-> E_P21 E + P2 <-> E_P2 E_P21 -> E + T E_P2 -> E + T E_P_1 -> T E_P_2 -> T