(* abc_box_id = 1 *) module SB_CARRY (output CO, input CI, I0, I1); assign CO = (I0 && I1) || ((I0 || I1) && CI); endmodule (* abc_box_id = 2 *) module SB_LUT4 (output O, input I0, I1, I2, I3); parameter [15:0] LUT_INIT = 0; // Indicate this is a black-box assign O = 1'b0; endmodule