NIBO2 - line2 - Unbekannte Operatoren '?' und ':' in C-Code

//Copyrighthinweise...

//includes, defines, ...

int main() {

  //inits...

  copro_ir_startMeasure();

  delay(10);

  //motco_setSpeedParameters(5, 4, 6); // ki, kp, kd

  copro_setSpeedParameters(15, 20, 10); // ki, kp, kd

  int16_t speed_flt_l=0;

  int16_t speed_flt_r=0;

  while(1) {

    sei();

    _delay_ms(1);

    int16_t speed_l=0;

    int16_t speed_r=0;

    floor_update();

    char text[20]="--  --  --  --  --";

    // Bodensensoren

    floor_update();

    //Displayausgaben ...

    int16_t lval = floor_relative[LINE_LEFT];    //hier werden die Werte der

    int16_t flval = floor_relative[FLOOR_LEFT];  //Boden- und Liniensensoren

    int16_t frval = floor_relative[FLOOR_RIGHT]; //in temporären Variablen

    int16_t rval = floor_relative[LINE_RIGHT];   //gesichert

    int16_t cval = (flval>frval)?flval:frval;    //und was geschieht hier?

    //...

  }

  return 0;

}