how to define "when" statement with bus pins in state dependent timing arc?

[zhoulin999]

bus(rom_nodummy_rden_dly) {
      bus_type : bus_2_1_0 ;
      direction : input ;
    }

    pin(rom_nodummy_rden_dly[1:0]) {
      capacitance : 0.05 ;
      direction : input ;
      fall_capacitance : 0.01 ;
      fall_capacitance_range(0.008, 0.1);
      max_transition : 1.8 ;
      rise_capacitance : 0.01 ;
      rise_capacitance_range(0.008, 0.1);
    }

    pin(in) {
      capacitance : 0.04 ;
      direction : input ;
      fall_capacitance : 0.04 ;
      fall_capacitance_range(0.04, 0.041);
      max_transition : 1.8 ;
      rise_capacitance : 0.04 ;
      rise_capacitance_range(0.04, 0.042);
    }

    pin(out) {
      direction : output ;
      function : "in" ;
      max_capacitance : 0.0360106 ;
      max_transition : 1.8 ;

      timing() {
        related_pin : "in" ;
        timing_sense : positive_unate ;
        when : "!rom_nodummy_rden_dly[1] & !rom_nodummy_rden_dly[0]";
        sdf_cond : "rom_nodummy_rden_dly == 2'h0";

How to write the second line from bottom in above example?