module fn02d1 (zn, a, b, c);
   input a, b, c;
   output zn;
   and                  G3(N3, a, c);
   not                  G6(zn, N7);
   or                   G7(N7, N8, N9, N3);
   and                  G8(N8, a, b),
                        G9(N9, b, c);
endmodule