.model top
.inputs cin a0 a1 b0 b1
.outputs s0 s1 cout
.names cin a0 a1 b0 b1 s1
000-1 1
001-0 1
0-001 1
0-100 1
110-0 1
111-1 1
1-010 1
1-111 1
-0001 1
-0100 1
-1010 1
-1111 1
.names cin a0 b0 s0
001 1
010 1
100 1
111 1
.names cin a0 a1 b0 b1 cout
111-- 1
11--1 1
1-11- 1
1--11 1
-111- 1
-1-11 1
--1-1 1
.end