# (x1 V ¬X2) ∧ (¬x1 V ¬X3) ∧ (x3 V x4) ∧ (¬x2 V ¬X4) ∧ (x2 V ¬x4) 

1 -2
-1 -3
3 4
-2 -4
2 -4