c an ALC problem
p cnf 8 19
-1 2 0
-3 2 0
-1 -4 0
-1 -5 0
-3 -4 0
-3 -5 0
-1 -6 0
-3 -6 0
-7 2 0
-8 2 0
-7 -4 0
-7 -5 0
-8 -4 0
-8 -5 0
-7 -6 0
-8 -6 0
1 7 0
3 8 0
-2 5 6 0