module bb2 ( input x, input y, input cin, output A, output cout ); `ifndef BUG assign {cout,A} = cin + y + x; `else assign {cout,A} = cin - y * x; `endif endmodule module top2 ( input x, input y, input cin, output A, output cout ); bb2 u_bb2 (x,y,cin,A,cout); endmodule