library(top) {

 /* unit attributes */
  time_unit : "1ns";
  voltage_unit : "1V";
  current_unit : "1uA";
  pulling_resistance_unit : "1kohm";
  leakage_power_unit : "1nW";
  capacitive_load_unit(1,pf);


  cell(top) {
    pin(regA) {
	direction : output ;
	capacitance : 0.001;
	function : "(y | x & cin)";
    }
    pin(regcout) {
	direction : inout ;
	capacitance : 0.001;
	function : "(y + x & cin ^ regA)";
    }
    pin(x) {
	direction : input ;
	max_transition : 2.5;
	capacitance : 0.001;
    }
    pin(y) {
	direction : input ;
	max_transition : 2.5;
	capacitance : 0.001;
    }
    pin(cin) {
	direction : input ;
	max_transition : 2.5;
	capacitance : 0.001;
    }
  }
}