.PS
log_init

# Usual defs...
qrt=dimen_/4;
hlf=dimen_/2;
dim=dimen_;

C1: Here
G1:XOR_gate
line from G1.In1 left_ 2*L_unit; dot; line left_ 4*L_unit
"$A_0$ " ljust_;
line from G1.In2 left_ 4*L_unit; dot; line left_ 2*L_unit
"$B_0$ " ljust_
move down_ 6*L_unit; right_
G2:AND_gate with .center at (G1.center,Here)
line from G2.In1 left_ 2*L_unit; line to (Here,G1.In1)
line from G2.In2 left_ 4*L_unit; line to (Here,G1.In2)
P2:G2.Out
line from G1.Out right_ 25*L_unit
P1:" $C_0$" ljust_
move to G1.Out then up_ 2*L_unit; "Sum" ljust
move to G2.Out then up_ 2*L_unit; "Carry" ljust


move to C1 then down_ 18*L_unit;right_
G1:XOR_gate 
line from G1.In1 left_ 6*L_unit
"$A_1$ " ljust_; 
line from G1.In2 left_ 6*L_unit
"$B_1$ " ljust_
move to G1.center then down 8*L_unit;right_
G2:AND_gate with .center at (G1.center,Here)
line from G2.In1 left_ 2*L_unit
line to (Here,G1.In1); dot
line from G2.In2 left_ 4*L_unit
line to (Here,G1.In2);dot
line from G1.Out right_ 10*L_unit
G3:XOR_gate with .In2 at Here
line from G3.In1 left_ 6*L_unit 
line to (Here, P2); line to (P2, Here)
move to G3.Out then up_ 2*L_unit; right_; "Sum" ljust_
move to G3.Out; line to (P1,Here); " $C_1$" ljust_
move to G3.center then down_ 8*L_unit; right_
G4:AND_gate with .center at (G3.center,Here)
line from G4.In1 left_ 2*L_unit
line to (Here,G3.In1); dot
line from G4.In2 left 4*L_unit
line to (Here,G3.In2); dot
move to G4.center then down_ 8*L_unit; right_
G5:OR_gate with .center at (G4.center,Here)
line from G5.In1 left_ 2*L_unit then up_ 2.5*L_unit
line to (G4.Out,Here) then right_ 2*L_unit
line to (Here,G4.Out) then to G4.Out
line from G5.In2 left_ 6*L_unit
line to (Here,G2.Out) then to G2.Out
move to G5.Out
P3:Here
move up_ 2*L_unit; right_; "Carry" ljust_


move to C1 then down_ 42*L_unit;right_
G1:XOR_gate
line from G1.In1 left_ 6*L_unit
"$A_2$ " ljust_; 
line from G1.In2 left_ 6*L_unit
"$B_2$ " ljust_
move to G1.center then down 8*L_unit;right_
G2:AND_gate with .center at (G1.center,Here)
line from G2.In1 left_ 2*L_unit
line to (Here,G1.In1); dot
line from G2.In2 left_ 4*L_unit
line to (Here,G1.In2);dot
line from G1.Out right_ 10*L_unit
G3:XOR_gate with .In2 at Here
line from G3.In1 left_ 4*L_unit then up_ 2.5*L_unit then right_ 14*L_unit
line to (Here,P3); line to (P3,Here)
line from G3.Out to (P1,G3.Out);  " $C_2$" ljust_
move to G3.Out then up_ 2*L_unit; right_; "Sum" ljust_
move to G3.center then down_ 8*L_unit; right_
G4:AND_gate with .center at (G3.center,Here)
line from G4.In1 left_ 2*L_unit
line to (Here,G3.In1); dot
line from G4.In2 left 4*L_unit
line to (Here,G3.In2); dot
move to G4.center then down_ 8*L_unit; right_
G5:OR_gate with .center at (G4.center,Here)
line from G5.In1 left_ 2*L_unit then up_ 2.5*L_unit
line to (G4.Out,Here) then right_ 2*L_unit
line to (Here,G4.Out) then to G4.Out
line from G5.In2 left_ 6*L_unit
line to (Here,G2.Out) then to G2.Out
line from G5.Out to (P1,G5.Out); right_; " Carry Out" ljust_

move to G5.Out then down_ 6*L_unit
"\tiny 3BitAdder" ljust_ 
.PE