lib.v

module invert(output ib,input b);
	assign ib = ~b;
endmodule

module and2 (input wire i0, i1, output wire o);
  assign o = i0 & i1;
endmodule

module or2 (input wire i0, i1, output wire o);
  assign o = i0 | i1;
endmodule

module xor2 (input wire i0, i1, output wire o);
  assign o = i0 ^ i1;
endmodule

module nand2 (input wire i0, i1, output wire o);
   wire t;
   and2 and2_0 (i0, i1, t);
   invert invert_0 (t, o);
endmodule

module nor2 (input wire i0, i1, output wire o);
   wire t;
   or2 or2_0 (i0, i1, t);
   invert invert_0 (t, o);
endmodule

module xnor2 (input wire i0, i1, output wire o);
   wire t;
   xor2 xor2_0 (i0, i1, t);
   invert invert_0 (t, o);
endmodule

module and3 (input wire i0, i1, i2, output wire o);
   wire t;
   and2 and2_0 (i0, i1, t);
   and2 and2_1 (i2, t, o);
endmodule

module or3 (input wire i0, i1, i2, output wire o);
   wire t;
   or2 or2_0 (i0, i1, t);
   or2 or2_1 (i2, t, o);
endmodule

module nor3 (input wire i0, i1, i2, output wire o);
   wire t;
   or2 or2_0 (i0, i1, t);
   nor2 nor2_0 (i2, t, o);
endmodule

module nand3 (input wire i0, i1, i2, output wire o);
   wire t;
   and2 and2_0 (i0, i1, t);
   nand2 nand2_1 (i2, t, o);
endmodule

module xor3 (input wire i0, i1, i2, output wire o);
   wire t;
   xor2 xor2_0 (i0, i1, t);
   xor2 xor2_1 (i2, t, o);
endmodule

module xnor3 (input wire i0, i1, i2, output wire o);
   wire t;
   xor2 xor2_0 (i0, i1, t);
   xnor2 xnor2_0 (i2, t, o);
endmodule



module fa (input wire i0, i1, cin, output wire sum, cout);
   wire t0, t1, t2;
   xor3 _i0 (i0, i1, cin, sum);
   and2 _i1 (i0, i1, t0);
   and2 _i2 (i1, cin, t1);
   and2 _i3 (cin, i0, t2);
   or3 _i4 (t0, t1, t2, cout);
endmodule