module MUX21_NPMOS (MXOUT, SEL, D0, D1);
  output MXOUT;
  input  SEL;
  input  D0;
  input  D1;

  nmos  nm1 (net1, D1, SEL);
  pmos  pm1 (net1, D0, SEL);

  nmos  nm9 (MXOUT, net1, 1'b1);

endmodule